Well the mulch area is in middle of my front lawn, a good couple of feet from the road. Driveway, grass or mulch area, I think its a d!ck move regardless.if he threw the dead squirrel into your 'mulch', then I would equate it, to using your garbage can to throw out a candy wrapper. not a big deal. that's where candy wrappers GO, afterall.
(IF he had thrown it into YOUR driveway, as opposed to his OWN driveway, then yeah.... dude's a *****. no excuse).