It seems common for a heart-shot deer to drop to his knees or even fall completely to the ground and then get up and run for some distance. I'll call it luck that any of my "long distance runners" have gone no more than 100 yards, and were in open country when shot. I'm talking here about using a .270 and a .30-'06. Some of my deer, shot with those, just folded up and died...
gdeal, you shoot a deer in the white spot with a .222 and they fall down instantly ruined and don't go anywhere at all. That was the case for my first deer, back around 1950.
I've killed over 20 deer with a .243; mostly neck shots. DRT. "Never went nowhere."
You're from BATFE? Come right in! I use all your fine products!