Well, most crocs are saltwater. That doesn't mean they won't venture into fresh. And don't confuse them with Kamen.
The guy was lucky. Crocs like to drag their prey down into the deep and shove them under a rock or a sunken log for a couple days. It tenderizes the meat so they can devour them easier. It's kind of like aging a steak. It's one of the reasons I don't eat aged beef.