Most humans’ instincts when they see a gun is to do whatever it takes to get it pointed away from them. This said gun can, after all, kill you.
This jewelry store owner’s reaction when he saw the gun, however, was to get the robber the hell out of his store by any means necessary without any of his jewels. The means available to him just so happened to be a bat, and that was plenty enough.
This robber sucks at life, because he can’t do anything right. He had the gun pointed at the owner but still couldn’t hit him.