Not trying to impugn your results there. I see what you do.
The Muzzy is a good head, been around for a while. That bow and arrow / head combination is lethal, for sure.
Just saying that the deer is not static. Even a little movement on its part, or of its parts makes a big difference.
BTW, shoot the shoulder blade and the board with a blunt. If you have enough bow, it will blow thru either better than a broadhead because it punches a hole the size of the shaft, not just a slit.
Also BTW, our bows do not generate the amount of force to be able to knock a healthy deer over (without a spine impact) or even make it skid.
Lastly.... please don't go away till next fall, keep talking to us all year, your company is welcome.
ChuckC