Standard behaviour from a lot of shooters, they aren't sports men, just shooters....there is a massive difference between the two.
I had a cracking pond on some moorland and a couple of local lads asked if they could buy a flight, I said no as I genuinely wasn't allowed to take guests on for various reasons linked to landowners and tennants, I was lucky to be on there myself. Anyway the two lads went up regularly training their dogs at last light on the edge of the pond to put the ducks off.
I've known loads of instances like that.