Lying to your bioss is a no-no. Especially getting caught at it. He had to go.
Speaking to Russia 5 weeks before he was "allowed" to is really inconsequential.
Take John Kerry. (Please!).
Traitor John spoke as a "private" citizen to North VietNam envoys while we were at war.
Treason.
Twice (at least)
Treason again.
He was still in Navy Reserve at the time- Treason a third time, right up there with Benedict Arnold.
This qualified him to be a Senator, and then Secretary of Defense under Democratic auspices.