In my experience, if you do your part, a deer's reaction to being shot has always been the same...THEY DIE!!!
Seriously though, I can't emphasize enough how important it is to pay attention to a deer's reaction (& direction of flight) after the shot. Always follow-up a shot, even if you're "sure" you missed. Look for blood, hair, bits of bone, or irregular tracks away from the site. An untold number of "missed" deer (& other game animals for that matter) have run off at the shot only to die elsewhere unbeknownst to the hunter. Put at least as much effort into your follow-up after the shot as you did in locating your game in the first place.