You are correct, just as stunt men can fall off a bike without injuring themselves, riders know when it is relatively safe to drop the bike and yes, in some countries riders are taught to lay the bike down, something that should be done here.
You would never see a rider go headlong into the fence (ie, straight on) to get a re-run because that would be crazy but it's pretty easy to lay a bike down without causing too much damage once you learn how and it becomes second nature, or at least it should. It's a case of learning how to fall.
One thing riders learn very quickly is if you're going to crash hard, don't hold onto the bike. Also the more you tense, the more likely you are to break something, but it's not always easy to relax when you're traveling in the air at 60mph!