ORIGINAL: Tree climber

if he was on his property and doing nothing illeagle , then you have nothing to be mad about.telling him off when he has a gun , could be a bad thing.
if shooting from a truck is legal in your state , then he has done nothing wrong.as for seeing you, "last light" , he may not have saw you.it's hard to say.

sorry you didn't get you meat deer.maybe you will get another chance.