Dave didn't know that man, but he saw a few pictures, and knew from Claire's look that he was indeed who he thought he was... the ex husband. There was nothing Dave could do right now, and the man had a gun anyway, so he decided to cooperate for now. He had better appear non dangerous, and as soon as Thomas dropped slightly his guard, Dave would juwp at him and neutralize him. Gun or no gun, he wouldn't be able to keep an eye on both of them at all times...