After re-reading everything a few more thoughts.
First, sorry if I came across somewhat self-righteous. I don't have much of a sense of humor before my first cup of coffee.
AKKK. well, to the credit of both, uke walked away, if a bit loopy. That was one heckofa breakfall. I have no idea how to train for that.
Second. How would the "break-the-wrist" approach work with uke? Well, if I'm uke, you might well break my wrist: I've really flexible wrists (sensei calls me "Gumby" once in a while), and I often don't feel pain till the very last, then it comes on very fast. I probably would never train with you again. If you're defending yourself against someone who's high on crystal meth, they might not notice that you've broken their wrist and fail to fall down. If your uke is a big brawny experienced fighter, he may get in a few shots with his other weapons, since you haven't broken his balance before you break his wrist, or he may be able to muscle out of it. Or if you do break his wrist and get to walk away, his buddies will probably come after you with worse for breaking their buddy's wrist. People tend to take that kind of damage more seriously than a simple humiliation.