According to Article III:
"No Person shall be convicted of Treason unless on the Testimony of two Witnesses to the same overt Act, or on Confession in open Court. ... The Constitution defines treason as specific acts, namely "levying War against [the United States], or in adhering to their Enemies, giving them Aid and Comfort."
Is this how Trump defines treason? I'd prefer that our President, any President, would be more precise in his use of that word. The "aid and comfort" can be loosely defined, but I'm just a bit uncomfortable with the charge being tossed out there without giving any proof to back it up.
Those two FBI agents should be fired, but they should also be accorded their rights under civil service regulations.