From How far would you need to fall for it to be fatal? answer on another stack, backed by NASA documents:
- it depends a lot on where and which way up you land - feet-first onto a soft surface is best (pretty obvious)
- For a hard surface, assuming you don't land on your head, up to about 12m/s impact velocity, you are almost certain to survive (corresponding to a fall from a height of just over 7m). Though "survive" is likely to involve life-changing injuries at the top of this range
7 meters being 22.9 feet. Just over 2 Stories of a standard building (Roughly 10 feet each story). Eyeballing it, based on the height of the wall divisions, and general number of steps required to get to the top, the raptor pen does seem to be around 20 feet/2 stories.
The character lands on soft wood chips on top of soft dirt, not hard concrete. And he doesn't land on his head. He flops on his back, kinda. He falls, braces a bit with his arm and leg.
It's unlikely that he would have any life risking injuries, but if you ever belly or back flopped in a pool, you know he will be in pain later that day. Bruising, swelling, soreness, at minimum, maybe a dislocated shoulder or cracked coccyx at worst.
The character also doesn't get up and run, he crawls, backwards, to the cage door, and is still sitting down when Owen escapes the pen. When he gets up, and the camera pulls out, he gets up Limping and Stumbling out.