Most likely he was trolling and not snagging.

I think poaching means if you knowingly take an illegal fish. It sounds nasty and he fits the definition but I wouldn't call him that.

... but he committed an illegal act by keeping the fish. Sounds like it was his first time and he went by what feels right to him.

Now he knows and he won't repeat and also won't be able to run for any office since we have a documented case ...