Seen ity done a few times..owned a dog that did it fairly regular...the reason i know they were dead was because i checked...the old finger on the eyeball trick...i still do that with foxes now just to make sure...no one likes to leave a fox in the hedge bottom without knowing one way or the other if its dead or not....just imagine a 90 to 100lb dog hitting you in the ribs at 35mph...think you,d be in hospital with at least a few broken ribs..or maybe worse..atb stabba