That’s what ‘derp’ means, actually. Really funny you said that.
Basically saying something that only town would say where they have some kind of lack of understanding about the mafia or something that happened in the game.
It can and has been faked many times before, especially by the likes of PKR. I wouldn’t really read into that too much (although realistically I understand why he said that because in this setup and the game it’s based on cult have 2 kills on non-convert nights)