The grenade was not something Wesker wanted to see. As it rolled towards him he took off, a blindingly fast dash not quite directly at the two Vampires but in between them.

He didn't think it would actually kill the vampire, but he did want to express his irritation over it by throwing one of the vampires after its own grenade. At the very least, it should keep him occupied while he handled the other one.

Since bullets had dropped it before, Wesker emptied the rest of the clip into the same vampire he'd shot moments before. He just needed to get it on the ground long enough to crush its head with his boot.