This is why the 243 gets a bad wrap as a deer cartridge. Your friend had no business hunting deer with an 80 gr bullet. Had he been using a 100 gr bullet, you'd be loading your freezer right now, and not worrying about where the deer is.

Addressing your question however, you've gotten some really good advice from the other posts. Start walking semi-circles in the direction the deer was last headed. Also, you and your friend should look for any possible sign....kicked up dirt, broken branches, hair, blood.

I doubt he would have jumped the fence. Most often, deer don't jump fences after they've been hit. But just in case, look just on the other side of it b/c landing would have taken a lot out of him.

Also, in the future, give the deer 20 mins minimum after the shot.

Good luck