a friend of mind missed the same deer 3 times too....
this is what you need to do,,,,, first lets a take a compound shooter with a pin, when he shoots ne needs to hold the pin onm the spot until impact no matter what..
traditional shooter, when he shoots he must pick a spot and keep picking that spot when he releases and when the arrow either hits or misses,,, if you see your arrow fly right through that spot then you did everything right if you see the deer jump the string and move out of the way But the arrow STILL flys through that spot your looking at (eventhough now the deers not part of it) thats still a good shot..... now if you shoot and the deer does not move before the arrow wounds or misses and the arrow does not hit where you are looking then that is your fault and has nothing to do with picking a spot because at that point essentially your Brain sights are off and you just are not hitting the spot you are picking--> that just takes more practice or dicipline meaning you might be beyond your comfort zone.
this is my quick way to determine if its ME that missed or the deer just out smarted me upon the shot.