Neither - if either of nage in the two clips had turned out, perhaps half-way through the technique, intending suddenly to break uke's arm, uke could do nothing about it, because he is committed to taking a back fall. Uke should turn towards nage, with his head against his own arm, "intending" to take a forward roll/tobu ukemi. IF and only IF tori clearly does a shihonage without bridging the arm, uke can then "sit up" into a back ukemi.
Thank you Ellis - I have your fine video and I recall now that you highlighted this in particular on it. I'll have to go back and review.
What's your general take on the idea of taking ukemi on your shoulder blades as in the first example? It strikes me as insane but I've been told by those more knowledgeable than I that it's actually more protective during a fast, hard shihonage. Any validity to that?