Dante was far more than experienced enough to handle something like this... usually. Something was very wrong here, and not just because he screwed up badly.

That being said, he wasn't stupid enough to assume that the monster was dead, but it had more strength than he expected. He managed to yank the sword back out of the beast, but it knocked him aside before he had a chance to deliver the finishing blow, sending the sword a few feet to the left of Alba.