Lynching Siren would actually not prove that Titan is telling the truth because if Titan was a Cult member he'd know who wasn't guilty and could use that to say Siren is sane because he knows she is. On the flip side, he could be telling the truth and the dud situation could have been because the Dud was once a bomb or thought he was a bomb, I'm not sure. That is still a very odd thin that happened.