Gator discussion

One of my friends had a gator encounter recently at a wading spot we fish. No incident but the gator was definitely interested in what they were doing and didn't seem afraid at all. The gator was 6+ ft.

If the situation escalated a bit and they had to shoot the gator what should they do? Call DNR? Let nature take it's course? Hide the carcass? Drag it home?

We're talking a self-defense situation, not hunting.