So who killed Coco?!

I don't think that's right. I thought Jim Buck killed the wrong man at that point and we see Coco gloating because he has set the whole thing up. But later in the film, somewhere around 1:16, two men arrive in a car and give Coco's glasses to George, another killer and Rod Steiger's bodyguard. I have no idea who these two men were but perhaps his friend Mr Wong sorted it out or perhaps his fellow killers?