Story highlights Family friend: "We're leaving the politics to everybody else"

Pentagon spokesman: "We really don't know why he left the base"

Soldiers who served with Bergdahl say he should face military trial

Questions surround the circumstances of Bergdahl's disappearance

The sense of pride expressed by officials of the Obama administration at the release of Army Sgt. Bowe Bergdahl is not shared by many of those who served with him: veterans and soldiers who call him a deserter whose "selfish act" ended up costing the lives of better men.

"I was pissed off then, and I am even more so now with everything going on," said former Sgt. Matt Vierkant, a member of Bergdahl's platoon when he went missing on June 30, 2009. " Bowe Bergdahl deserted during a time of war, and his fellow Americans lost their lives searching for him."

Vierkant said Bergdahl needs to not only acknowledge his actions publicly but face a military trial for desertion under the Uniform Code of Military Justice.

A reporter asked Defense Secretary Chuck Hagel on Sunday whether Bergdahl had left his post without permission or deserted -- and, if so, whether he would be punished. Hagel didn't answer directly. "Our first priority is assuring his well-being and his health and getting him reunited with his family," he said. "Other circumstances that may develop and questions, those will be dealt with later."

Photos: Photos: Released Guantanamo Taliban detainees arrive in Qatar Photos: Photos: Released Guantanamo Taliban detainees arrive in Qatar Released detainees arrive in Qatar – CNN has obtained photos from the purported Twitter account of Taliban spokesman Zabihullah Mujahid. The photos purportedly show the arrival of the Guantanamo detainees arriving in Doha, Qatar, after being released in exchange for U.S. Army Sgt. Bowe Bergdahl. This image allegedly shows Mullah Norullah Noori. Hide Caption 1 of 4 Photos: Photos: Released Guantanamo Taliban detainees arrive in Qatar Released detainees arrive in Qatar – The Twitter account says that this photo is of Khair Ulla Said Wali Khairkhwa. Hide Caption 2 of 4 Photos: Photos: Released Guantanamo Taliban detainees arrive in Qatar Released detainees arrive in Qatar – According to the Twitter account, this is Mullah Mohammad Fazl arriving in Qatar. Hide Caption 3 of 4 Photos: Photos: Released Guantanamo Taliban detainees arrive in Qatar Released detainees arrive in Qatar – Mullah Norullah Noori and Abdul Haq Wasiq can be seen in this photo, according to the Twitter account. Hide Caption 4 of 4

Photos: Guantanamo detainees swapped for Bergdahl Photos: Guantanamo detainees swapped for Bergdahl Five detainees at Guantanamo Bay were transferred to Qatar in exchange for the release of Army Sgt. Bowe Bergdahl, who was being held by the Taliban. Two senior administration officials confirmed the names of the released detainees, whose photos were obtained by WikiLeaks. Khair Ulla Said Wali Khairkhwa, seen here, was an early member of the Taliban in 1994 and was interior minister during the Taliban's rule. He was arrested in Pakistan and was transferred to Guantanamo in May 2002. During questioning, Khairkhwa denied all knowledge of extremist activities. Hide Caption 1 of 5 Photos: Guantanamo detainees swapped for Bergdahl Mullah Mohammad Fazl commanded the main force fighting the U.S.-backed Northern Alliance in 2001, and served as chief of army staff under the Taliban regime. Fazl was detained after surrendering to Abdul Rashid Dostam, the leader of Afghanistan's Uzbek community, in November 2001. He was transferred into U.S. custody in December 2001 and was one of the first arrivals at Guantanamo, where he was assessed as having high intelligence value. Hide Caption 2 of 5 Photos: Guantanamo detainees swapped for Bergdahl Mullah Norullah Noori served as governor of Balkh province in the Taliban regime and played some role in coordinating the fight against the Northern Alliance. Like Fazl, Noori was detained after surrendering to Dostam, the Uzbek leader, in 2001. Hide Caption 3 of 5 Photos: Guantanamo detainees swapped for Bergdahl Abdul Haq Wasiq was the deputy chief of the Taliban regime's intelligence service. Wasiq claimed, according to an administrative review, that he was arrested while trying to help the United States locate senior Taliban figures. He denied any links to militant groups. Hide Caption 4 of 5 Photos: Guantanamo detainees swapped for Bergdahl Mohammad Nabi Omari was a minor Taliban official in Khost Province and was the Taliban's chief of communications and helped al Qaeda members escape from Afghanistan to Pakistan. He also said that he had worked with a U.S. operative named Mark to try to track down Taliban leader Mullah Omar. Hide Caption 5 of 5

JUST WATCHED Korder: Bergdahl 'at best a deserter' Replay More Videos ... MUST WATCH Korder: Bergdahl 'at best a deserter' 03:07

JUST WATCHED Bergdahl swap was only seconds long Replay More Videos ... MUST WATCH Bergdahl swap was only seconds long 02:12

Following his release from five years of captivity in Afghanistan on Saturday, Bergdahl was transferred to a military hospital in Germany.

A senior Defense official said Bergdahl's "reintegration process" will include "time for him to tell his story, decompress, and to reconnect with his family through telephone calls and video conferences."

Greg Leatherman was a sergeant in Bergdahl's platoon who supervised him but wasn't there the night he disappeared. He said, "I'm pleased to see him returned safely. From experience, I hope that he receives adequate reintegration counseling. I believe that an investigation should take place as soon as health care professionals deem him fit to endure one."

Another senior Defense official said Bergdahl will not likely face any punishment. "Five years is enough," he told CNN on condition of anonymity.

Questions surround the circumstances of Bergdahl's disappearance, and conflicting details have since emerged about how the militants managed to capture him. Published accounts have varied widely, from charges that he walked off the post to claims that he was grabbed from a latrine.

"We really don't know why he left the base and under what circumstances," Pentagon spokesman Rear Adm. John Kirby said Monday. Details of that will come out, he said, adding that the Army has never classified Bergdahl as a deserter and has scheduled the soldier for a promotion next month. But the details around a soldier being taken captive "don't matter," he said, when it comes to the military's response.

"We're going to do all we can to get you back," he said. "That's an obligation that we have, all the people that put on this uniform."

According to firsthand accounts from soldiers in his platoon, Bergdahl, while on guard duty, shed his weapons and walked off the observation post with nothing more than a compass, a knife, water, a digital camera and a diary.

At least six soldiers were killed in subsequent searches for him, according to soldiers involved in the operations to find him. The Pentagon was not able to provide details on specific operations in which any soldiers killed during that time were involved.

Also, many soldiers in Bergdahl's platoon said attacks seemed to increase against the United States in Paktika province in the days and weeks following his disappearance.

"Any of us would have died for him while he was with us, and then for him to just leave us like that, it was a very big betrayal," said former U.S. Army Sgt. Josh Korder, who has the name of three soldiers who died while searching for Bergdahl tatooed on his back.

Many of Bergdahl's fellow troops -- from the seven or so who knew him best in his squad to the larger group that made up the 1st Battalion, 501st Infantry Regiment, 4th Brigade Combat Team, 25th Infantry Division -- told CNN that they signed nondisclosure agreements agreeing to never share any information about Bergdahl's disappearance and the efforts to recapture him. Some were willing to dismiss that document in hopes that the truth would come out about a soldier who they now fear is being hailed as a hero, while the men who lost their lives looking for him are ignored.

"I don't think I could have continued to go on without being able to share with you and the people the true things that happened in this situation," Korder said Monday. "Because if you guys aren't made aware of it, it will just go on, and he'll be a hero, and nobody will be able to know the truth."

Traitor or hometown hero?

Many are flocking to social media, such as the Facebook page "Bowe Bergdahl is NOT a hero," where they share stories detailing their resentment. A number of comments on his battalion's Facebook page prompted the moderator to ask for more respect to be shown.

"I challenge any one of you who label him a traitor to spend 5 years in captivity with the Taliban or Haqqani, then come back and accuse him again. Whatever his intent when he walked away or was captured, he has more than paid for it."

As the chorus of criticism from some in Bergdahl's platoon grows louder, residents in his hometown of Hailey, Idaho, say their support of the soldier hasn't been shaken.

City officials released a statement saying they were being inundated with calls with concerns about Bergdahl's case and calling for people not to judge without knowing all the details.

"We're leaving the politics to everybody else. We're just glad to welcome Bowe back to us," family friend Stefanie O'Neill said. "We're going to let things play out when Bowe is able to tell his story."

Looking for adventure?

E-mails reported by the late Michael Hastings in Rolling Stone in 2012 reveal what Bergdahl's fellow infantrymen learned within days of his disappearance: He told people that he no longer supported the U.S. effort in Afghanistan.

"The future is too good to waste on lies," he wrote to his parents. "And life is way too short to care for the damnation of others, as well as to spend it helping fools with their ideas that are wrong. I have seen their ideas and I am ashamed to even be American. The horror of the self-righteous arrogance that they thrive in. It is all revolting."

Bergdahl wrote to them, "I am sorry for everything. The horror that is America is disgusting."

CNN has not independently verified the authenticity of the e-mails.

Spc. Cody Full, a former member of Bergdahl's squad, tweeted this weekend that before he disappeared, Bergdahl once told him, "If deployment is lame, I'm going to get lost in the Mountains and make my way to China."

Leatherman told CNN that Bergdahl "always looked at the mountains in the distance and talked of 'seeing what's on the other side.' "

Full noted in his Twitter recollections a story that others from Blackfoot Company relay. While soldiers were searching for Bergdahl, a platoon "came upon some children, they asked him have they seen an American. The children said 'yes, he was crawling on his belly through weeds and acting funny a while ago,' " according to Full.

The platoon went to the village where the children said the American had gone. "Villagers said an American did come through the area and was wanting water and someone who spoke English," Full shared.

Korder says he believes Bergdahl was looking for an adventure "without having anybody to answer to" when he left his post.

"He wanted to go see Afghanistan for himself without the Army stopping him or having to tell him what to do," Korder said.

Soldiers died during search

Former Pfc. Jose Baggett, 27, of Chicago, was also in Blackfoot Company and said he was close to two men "killed because of his (Bergdahl's) actions."

"He walked off," Baggett told CNN. "He left his guard post. Nobody knows if he defected or he's a traitor or he was kidnapped. What I do know is, he was there to protect us, and instead he decided to defer from America and go and do his own thing. I don't know why he decided to do that, but we spent so much of our resources, and some of those resources were soldiers' lives."

Many soldiers on the ground at the time said insurgents were able to take advantage of the intense search for Bergdahl.

"A huge thing in-country is not building patterns. Well when you are looking for a person every day that creates a pattern. While searching for him, ambushes and IEDs picked up tremendously. Enemy knew we would be coming. IEDs started being placed more effectively in the coming weeks. Ambushes were more calculated, cover and concealment was used," Full tweeted.

On August 18, 2009, Staff Sgt. Clayton Bowen and Pfc. Morris Walker were killed by an IED in the search for Bergdahl. Staff Sgt. Kurt Curtiss was killed on August 26; 2nd Lt. Darryn Andrews and Pfc. Matthew Michael Martinek were killed after being attacked in Yahya Khail District on September 4; Staff Sgt. Michael Murphrey was killed September 5 by an IED at the Forward Operating Base, Sharana.

Moreover, other operations were put on hold while the search for Bergdahl was made a top priority, according to officers who served in Afghanistan during that time. Manpower and assets -- such as scarce surveillance drones and helicopters -- were redirected to the hunt. The lack of assets is one reason the closure of a dangerous combat outpost, COP Keating, was delayed. Eight soldiers were killed at COP Keating before it was ultimately closed.

One soldier with the 509th Regiment, a sister unit of the 501st, told CNN that after Bergdahl disappeared, the U.S. Army essentially was told to lock down the entire province of Paktika. He described sitting in the middle of a field with his platoon, vulnerable, with capabilities and personnel mismanaged throughout the region. Different platoons ran out of water, food and ammunition.

Two mortarmen -- Pvt. Aaron Fairbairn and Pfc. Justin Casillas -- were killed in a July 4, 2009, attack.

"It was unbelievable," the soldier said. "All because of the selfish act of one person. The amount of animosity (toward him) is nothing like you've ever seen before."

That Bergdahl was freed in an exchange for five detainees at Guantanamo Bay is a further source of consternation.

"I don't understand why we're trading prisoners at Gitmo for somebody who deserted during a time of war, which is an act of treason," Vierkant said.