Lt. Col. Vindman cheered on social media for correcting Devin Nunes during impeachment hearing

Lt. Col. Alexander Vindman, an Army officer at the National Security Council, testified before the House impeachment hearings on Nov. 19, 2019. Lt. Col. Alexander Vindman, an Army officer at the National Security Council, testified before the House impeachment hearings on Nov. 19, 2019. Photo: Screenshot Via Twitter Photo: Screenshot Via Twitter Image 1 of / 53 Caption Close Lt. Col. Vindman cheered on social media for correcting Devin Nunes during impeachment hearing 1 / 53 Back to Gallery

Lt. Col. Alexander Vindman, an Army officer at the National Security Council, is the first active military member to testify during the House impeachment hearings — and he wanted to make sure Rep. Devin Nunes didn't forget that.

Nunes, a Republican representing California's 22nd congressional district, was attempting to get Vindman to reveal the name of the anonymous whistleblower whose initial complaint about a July phone call between President Donald Trump and Ukrainian president Volodymyr Zelenskiy triggered this impeachment probe. It's been alleged that on the call, Trump pressured Zelenskiy to investigate Democrat Joe Biden in exchange for U.S. military aid.

"Mr. Vindman, you testified in your deposition that that you did not know the whistleblower," Nunes said on Tuesday morning.

"Ranking Member," Vindman corrected, "it's Lt. Col. Vindman, please."

Nunes: "Mr Vindman, you testified in your deposition that that you did not know the whistleblower."



Vindman: "Ranking member it's Lt. Col. Vindman, please."pic.twitter.com/ittG8hkszM — The Washington Post (@washingtonpost) November 19, 2019

When Vindman insisted he didn't know the identity of the whistleblower, Nunes pressed harder.

"You can plead the fifth, but you’re here to answer questions," he said, prompting Rep. Adam Schiff, the Democrat chairing the probe, to interrupt.

"These proceedings will not be used to out the whistleblower," Schiff said.

In addition, Vindman sparred with Rep. Jim Jordan, R-Ohio, who called into question Vindman's professional credibility.

ALSO: GOP lawyer's facial expressions and questioning steal the show at impeachment hearing

"Your boss had concerns about your judgement, your former boss, Dr. [Fiona] Hill, had concerns about your judgement. Your colleagues had concerns about your judgement. And your colleagues felt there were times when you leaked information," Jordan said. "Any idea why they have those impressions, Colonel Vindman?"

In response, Vindman read from his last performance review from Hill: "Alex is a top one-percent military officer and the best Army officer I've worked with in my 15 years of government service. He is brilliant, unflappable and exercises excellent judgment."

Rep. Jim Jordan to Vindman: "Your boss had concerns about your judgment. Your former boss, Dr. Hill, had concerns about your judgment. Your colleagues had concerns about your judgment. And your colleagues felt there were times when you leaked information." #VindmanTestimony pic.twitter.com/7fjPDqhDRq — The Hill (@thehill) November 19, 2019

In further testimony, Vindman said Trump’s remarks strayed from the talking points prepared for the president.

“Without hesitation, I knew I had to report this,” Vindman testified. “It was inappropriate, it was improper for the president to demand an investigation into a political opponent.”

Vindman said the uneven power dynamic between the presidents of the East European ally and the U.S. made the demand obvious.

“The culture I come from, the military culture, when a senior asks you to do something ... it’s not be taken as a request, it’s to be taken as an order.”

It wasn’t the first time Vindman, a decorated Iraq War veteran, was alarmed over the administration’s push to have Ukraine investigate Democrats, he testified.

Earlier, during an unsettling July 10 meeting at the White House, Ambassador Gordon Sondland told visiting Ukraine officials that they would need to “deliver” before next steps, which was a meeting Zelenskiy wanted with Trump, the officer testified.

“He was talking about the 2016 elections and an investigation into the Bidens and Burisma,” Vindman testified, referring to the gas company in Ukraine where Biden’s son Hunter served on the board.

"The Ukrainians would have to deliver an investigation into the Bidens," he said. "There was no ambiguity."

On both occasions, Vindman said, he took his concerns about the shifting Ukraine policy to the lead counsel at the NSC, John Eisenberg.

The Associated Press contributed to this report.

Katie Dowd is an SFGATE Senior Digital Editor. Contact: katie.dowd@sfgate.com | Twitter: @katiedowd