Me, I'd make the crocodile fearful of me.
Well, we eventually became able to kill crocodile, but we have not succeeded in making them fearful of us. But for purposes of this exercise in imagination, I was assuming a small, weak hominid and wondering why they would let themselves be crocodile food except as a very occasional accident. It's not like 40,000 people have to migrate they herd across the river to get to the wintering grounds, and they are willing to lose a few along the way. We are talking about small bands of people, and even if they have very rudimentary brains, they ought to be smart enough to stay away from the crocodile hole.