Since a CIA whistle-blower filed a complaint against Donald Trump for pressuring Ukraine to investigate his rivals, the president and his allies have insisted that his call with President Volodymyr Zelensky—which made up just one aspect of the complaint—was perfectly fine and in no way grounds for impeachment. There are numerous reasons that Democrats believe otherwise—the rough readout of the call itself, in which the president essentially ties nearly $400 million in military aid to the ask; the fact that the White House moved records of the call to a secret server reserved for highly sensitive issues of national security—and now it appears we’ve got another one!

Politico reports that Lt. Col. Alexander Vindman, the decorated Army officer who listened in on the July 25 call himself, told lawmakers this week that after being stunned by what he heard, he went to senior White House lawyer John Eisenberg to log his concerns. Eisenberg reportedly wrote down Vindman’s complaints on a legal pad and then consulted with his deputy, Michael Ellis, about what to do about the conversation. The attorneys decided to move records of the call to the National Security Council’s top secret codeword system, where only a small group of officials would be able to access it.

At that point, Vindman told lawmakers, he didn’t view the move as evidence of a cover-up, but he became quite disturbed when, several days later, Eisenberg told him not to tell anyone about the phone conversation, which doesn’t exactly track with the claim that it was perfectly fine and legal. (It was also a strange order given that Vindman’s job entailed coordinating with government agencies regarding Ukraine policy.) The NSC’s top Russia and Europe adviser, Tim Morrison, said in a deposition on Thursday that he was worried the July 25 call, which he listened to with Vindman, would leak and, per CNN, “was involved with discussions after the call about how to handle the transcript.”

Neither Eisenberg nor an NSC spokesperson replied to Politico’s requests for comment. The president and his affiliates have spent the week smearing Vindman, suggesting he’s a traitorous spy for Ukraine, because he was born there (and because they seemingly have no other defense). According to reporter Natasha Bertrand, the White House counsel’s office is currently conducting a review of any documents related to the campaign to pressure Ukraine to do Trump’s bidding, “in an effort to push back on the Democrats’ central charge—an allegation corroborated by several administration officials—that Trump withheld military assistance aid and a White House summit from the Ukrainians in exchange for Zelensky’s public commitment to investigate Trump’s political rivals.”

For his part, Eisenberg—who is known for the level of secrecy he demands—had been tipped off to concerns even before the call happened. A number of National Security Council officials reportedly complained to him several weeks prior about what they believed was a shadow Ukraine policy being run by Rudy Giuliani and U.S. Ambassador to the E.U. Gordon Sondland. Those officials included Fiona Hill, who went to Eisenberg on orders from then-National Security Adviser John Bolton. According to Hill’s testimony, Bolton instructed her to tell Eisenberg that he was “not part of whatever drug deal Sondland and [White House acting chief of staff Mick] Mulvaney are cooking up.” It’s unclear what happened after that, but after the CIA whistle-blower filed his complaint, the agency’s top lawyer called Eisenberg to discuss it, and the two men deemed the accusations reasonable. House Democrats have called Eisenberg to testify on November 4, but given the White House’s impeachment strategy thus far, it’s not at all clear he’ll actually show up.