I am NOT a profession stuntman, so take this with a grain of salt. But I've dropped my Harley twice, fell off of my share of ladders, and just doing stupid stuff climbing when I was younger. I assume the same concepts apply to a bicycle. The one thing most people do wrong is that they try and stay with the bike/ladder/bicycle, roof, etc. This is the opposite of what you want to do imo. My worst accident was when I dropped my Harley going about 40 after being cut off by a car. When I realized the bike was unrecoverable, I jumped off literally pushing and kicking it away from me. I slid a good long ways mostly on my bum and got some good road rash on my back and side
Ditto with a ladder. Don't try to go down with it! Push it away and land on your own terms if possible. This is true even if you're on some ledge. As soon as you realize you're in unrecoverable shape, jump on your own terms. Many times people hang on too long and get more seriously injured than necessary