I suspected that you used a fixed head. Falls in line with my beliefs about large mechanicals. The smaller diameter fixed heads zip through deer's ribs almost unnoticed. I have had the same experience with fixed heads in the past. The deer shrugs off the shot, walks a short distance and tips over. A large cut causes a lot of "trauma" to bones in addition to hemorrhaging. This gets the deer moving fast and they can cover a lot of ground if there is no obstacles. This year I have killed two deer with Ramcat fixed heads. Recovery was about 40 yds. I have shot deer with large mechanicals and they covered up to 150 yds in no time. Still am undecided if bigger is better or if it just appeals to our senses.
Well a little off subject. Don't want to take away from your success.