(CNN) Las Vegas gunman Stephen Paddock opened fire on a crowd at a music festival just 40 seconds after shooting a Mandalay Bay Resort and Casino security guard -- not six minutes later, the resort's owner said Thursday, disputing a police timeline.

The new statement from MGM Resorts International contradicts recent comments by authorities who say Paddock shot Jesus Campos through his hotel room door at 9:59 p.m., injuring him, before the gunman opened fire on the crowd six minutes later.

Initially, police said Campos had approached Paddock's room as the October 1 shooting was underway, diverting the gunman's attention. Paddock then shot Campos through the door and quit firing at concertgoers at the Route 91 Harvest Festival from his hotel room on the 32nd floor, the timeline said.

But MGM, which also owns the concert venue, said the time the security guard was reported shot is wrong.

"The 9:59 p.m. PDT time was derived from a Mandalay Bay report manually created after the fact without the benefit of information we now have. We are now confident that the time stated in this report is not accurate," MGM said.

"We know that shots were being fired at the festival lot at the same time as, or within 40 seconds after, the time Jesus Campos first reported that shots were fired over the radio," MGM said.

Police were with armed Mandalay Bay security officers in the building when Campos first reported shots were fired over the radio, the statement said. The officers and the armed security personnel immediately responded to the 32nd floor, MGM said.

Las Vegas Metro Police Department spokesperson Laura Meltzer said the department would not comment on the MGM statement.

The gunman's motive, the timeline of the shooting and why he stopped shooting are among the wealth of unanswered questions that persist after 11 days of investigation into the Las Vegas music festival massacre that left 58 people dead and injured nearly 500.

The lack of answers, especially about the timeline, seems all the more curious when, it would appear, many moments in the shooter's dayslong preparation -- and the actual assault -- were captured by hotel video surveillance or by cameras the gunman himself installed in his suite and hallway.

Clark County Sheriff Joseph Lombardo has asked the public for patience, saying authorities are trying to "draw the most accurate picture" of how the shooting unfolded.

Federal and local agencies continue collecting evidence, delving into the gunman's life and interviewing those close to him.

"There's more than 20,000 moving parts associated with this investigation and it takes time," the sheriff told CNN affiliate KLAS on Wednesday.

What happened in the 6 minutes after the hotel security guard was shot?

According to the police timeline, an open door to a room near Paddock's suite had set off an alarm, prompting Campos to respond to the floor. Once there, Campos heard a drilling sound from Paddock's room, and he was shot in the right upper thigh.

Paddock opened fire at 10:05 p.m. and unleashed bullets on concertgoers for about 10 minutes. The police didn't get to Paddock's 32nd-floor suite until 10:17 p.m. They didn't breach the room until 11:20 p.m., after a SWAT team arrived with explosive charges, Lombardo said.

It's unclear why Paddock stopped shooting into the festival crowd after 10 minutes.

When SWAT officers breached Paddock's door, they discovered the gunman dead, apparently of a self-inflicted gunshot wound.

Lombardo said Campos, upon being shot, notified security, and his action helped pinpoint the suspect's location.

Police didn't know Campos was shot until they met him on the 32nd floor, Lombardo said.

It's still unclear who Campos initially contacted and what happened in the six minutes between Campos being shot and Paddock opening fire on the festival. Also fuzzy: Why did it take 18 minutes for officers to reach the 32nd floor?

MGM, in a statement Thursday, said it would respond to Gasper's allegations "through the appropriate legal channels."

"As our company and city work through the healing process, our primary focus and concern is taking actions to support the victims and their families, our guests and employees and cooperating with law enforcement," it said.

Is the new timeline of events correct?

Lombardo told KLAS the timeline is not static.

"Nobody's trying to hide anything. What we want to do is draw the most accurate picture we can," Lombardo said. "That timeline might change again."

Responding to MGM, a law enforcement source close to the investigation said police stand by the timeline, calling it "pretty accurate with all the facts known."

How could he meticulously plan this kind of attack without anyone noticing?

Over several days, Paddock took guns and ammunition to his hotel suite. He had 23 weapons in his room. In his car were more than 50 pounds of explosives and 1,600 rounds of ammunition, police said. Twelve of the firearms had bump stocks -- legal accessories for rifles that enable them to be fired more rapidly.

Authorities also found a note containing calculations on distance and trajectory to the concertgoers below, according to a law enforcement source.

Lombardo said they have found "no evidence to show there was a second shooter."

Authorities have received 200 accounts of Paddock traveling around Las Vegas, and that he "has never been seen with anyone else," the sheriff said.

Through her attorney , Paddock's girlfriend, Marilou Danley, said it "never occurred to me in any way whatsoever that he was planning violence."

What was he planning to do with the explosives in his car?

Investigators learned Paddock had "personal protection equipment with him," Lombardo told reporters Monday, leading authorities to believe he planned more than a mass shooting.

"We know he attempted to shoot at fuel tanks," Lombardo said. "I would be comfortable saying, depending on the splash he made during the shooting, it would enable first responders to draw their attention to other locations, which would allow Paddock to just leave the hotel."

Why did he do it?

Authorities have received more than 1,000 tips but still have no credible information on Paddock's motive.

Lombardo admitted the slow speed of the investigation frustrated him.

"It's because this individual purposely hid his actions leading up to this event and it is difficult for us to find the answers to those actions," he said.

Nothing about Paddock's life provides clues as to why he would have meticulously planned and perpetrated mass murder. The 64-year-old retired accountant had no apparent political or religious affiliations , one of his brothers said.

Paddock would wager up to $1 million a night but wandered around casinos in sweatpants and flip-flops. He carried his own drink into the high rollers' area because he didn't want to tip the waitresses much, according to a deposition obtained exclusively by CNN that was part of a 2013 civil lawsuit Paddock brought against the Cosmopolitan Hotel over a fall.

He had no criminal record. His purchase of an arsenal raised no red flags.

"Currently, we do not believe there is one particular event in the suspect's life for us to key on," the sheriff said.

In the 2013 deposition, Paddock said he had no mental issues or addictions.

Over the years, he owned apartments and houses in Nevada, Florida and California. Most recently, he lived in a retiree community in Mesquite, Nevada, northeast of Las Vegas.

He kept a low profile . Some neighbors rarely saw him.

In September, Paddock rented a room at a Las Vegas condo complex that overlooked the Life Is Beautiful music festival.