Hello everyone! My first post here, I think.
Hmmm... I'll just stick to some key points to prevent the "spin out" part.
Okay, let's just get to the position of the technique just before nage raises their hands up. Nage and uke are, in effect ,"mirror" images of each other, with arms extended out in front. At this point, nage moves forward, towards uke's hand as it's being raised (Mr. Baker's post mentions this, but I thought I'd repeat it). *Then* pivots to complete the throw. Uke doesn't spin out because nage moves forward while keeping uke's hand/arm in the same relative position... that is ... extended. It doesn't occur to uke that they could spin out, because they can't.
Uke is able to spin out when nage stays "mirrored" and pivots to complete the throw without moving forward. Since uke is still a "reflection" of nage, they will naturally pivot in the same manner, especially when nage insists on putting uke's elbow in a vulnerable position.
Yep, it's common. But it can be remedied without reversing the technique, yanking (ouch! don't yank!), moving faster, cutting harder, etc.