Words mean things, and the word "treason" in particular is, alone among offenses, defined in the body of the Constitution. There's no circumstance in which Comey's actions could be "treasonous", even if they were done in bad faith.
Actually, it seems to be incredibly broad and could cover anything deemed to help the "enemy". Considering we don't declare war anymore this is either absolutely unenforceable, or is totally open-ended as to what an enemy is. (Is ISIS an enemy? The Free-Syrian Army? The Kurds?)
