It would appear that the assassin’s (tiny) pistol malfunctioned. Then Dogan (inexpertly) deflected the gun away from his face. The assassin gave up without much of a fight — and then took a beating from just about everyone present.
On the one hand, he was already subdued. On the other hand, it’s human nature to kick an attempted murderer when he’s down. It just is.
(Hat tip to Michael Yon.)