Lt. Col. Alexander Vindman and aide to Vice President Mike Pence Jennifer Williams testified for the impeachment inquiry Tuesday under a strict warning from House Intelligence Committee Chair Adam Schiff (D-Calif.) to not reveal details about the Ukraine whistleblower. But Ranking Member Devin Nunes (R-Calif.) still pushed Vindman to do so — and didn't get anywhere with it.

The whistleblower who sparked the impeachment inquiry wasn't actually on the call between President Trump and Ukraine's President Volodymyr Zelensky, but both Vindman and Williams were. So it already seemed sketchy when Nunes asked if Vindman gave a briefing on this call to anyone. Vindman answered that he had, and said they were "outside the White House with an appropriate need to know." After further prodding, Vindman revealed one of those people was state official George Kent and that the other was "in the intelligence community."

That's when things got testy. After Nunes asked for that person's specific identity, Schiff interjected, saying "we need to protect the whistleblower" while Republicans clearly objected in the background. Yet Nunes continued, asking how Vindman could be outing the whistleblower if he didn't know who it was. Vindman then deferred to his counsel and refused to go further in describing the other individual.

Watch the whole moment below. Kathryn Krawczyk