I mean 'HE DIDN'T ACT. I THOUGHT NO TOWN WOULD RISK THEMSELVES GETTING KILLED IN THAT SCENARIO.' is reasoning to support why he shot him. He's clearly trying to shoot mafia.
I don't even need to prove that I thought he was mafia because what happened is literally not hipfire. I communicated/had an exchange with the guy. Then he was shot. Me having to say I thought he was mafia isn't even necessary