> reporting what he believes to be illegal conduct to congress one one side.
“Former” cia analyst that was directly involved in the events being investigated by the administration is reporting through his friends to an associate in Congress about an “illegal” conduct. Sounds a bit more like covering up former shady deals for his political friends.
The question is usually "is it favorable to the CIA/NSA or not?".
Favorable (Vindman/Cia<mare>lla) -> whistleblower
Unfavorable (Snowden) -> leaker