Lt. Col. Yevgeny Vindman, a National Security Council attorney who never testified, fired with twin brother Lt. Col Alexander Vindman.

This comment was posted to reddit on Feb 08, 2020 at 11:37 am and was deleted within 1 day, 2 hour(s) and 44 minutes.

The White House’s stance was that those particular subpoenas could potentially violate executive privilege (every president uses that and has in legal proceedings) if lawyers couldn’t accompany them (having lawyers while being questioned under oath is a normal legal precedent)
you’re right he was, he’s probably confusing the other 16 of 18 witnesses who weren’t on the call and testified to a rumor they heard, although Vindman only testified that he disagreed with the admins policy on Ukraine not that he heard any crime at all being committed or even inappropriate
Vindman himself can be dismissed for any reason at any time from that position, (he’s still in the military unless he retires) testifying under oath that you don’t agree with the administrations policy makes a good case for being dismissed from that administration during downsizing. The administration has claimed the downsizing of that council started months before impeachment, and again neither are “fired”, just removed from that particular position