Moments after President Trump ended his phone call with Ukraine’s president on July 25, an unsettled national security aide rushed to the office of White House lawyer John Eisenberg.

Army Lt. Col. Alexander Vindman, the top Ukraine adviser at the White House, had been listening to the call and was disturbed by the pressure Trump had applied to Ukrainian President Volodymyr Zelensky to investigate his political rivals, according to people familiar with Vindman’s testimony to lawmakers this week.

Vindman told Eisenberg, the White House’s legal adviser on national security issues, that what the president did was wrong, said the people, who spoke on the condition of anonymity because of the ongoing investigation.

Scribbling notes on a yellow legal pad, Eisenberg proposed a step that other officials have said is at odds with long-standing White House protocol: moving a transcript of the call to a highly classified server and restricting access to it, according to two people familiar with Vindman’s account.