Some examples would be horses still being unable to cross hearthfires, which can sometimes be annoying when riding around.
A better example would be what happened to me recently. Was mining on a horse, spawned a troll, while running away, troll decided to aggro and attack my horse. The horse was KO'd but the troll was still affected by a hitbox. Now this occurred in a 1 tile long area, so the moment the troll KO'd the horse he had no way to get to me, making him cause a cave-in towards me at a range. It didn't kill me or anything, but I would have preferred the troll to keep chasing me.