Uke is obviously the most prone to injuries, but not always because of Nage. When you're tired or not concentrating you don't always anticipate well enough. I know that at the end of training I often don't flip over as fast or as far out of the techinque as I really should to escape. Sometimes then I've been hurt, wrenched or dumped on my neck (especially in Yoshinkan)
That's more about me giving in. Personally there is nothing more tedious than getting hurt by an inexperienced Nage/Sh'te, and it occurs in every martial art where thereis some element of sparring. The idiot is usually male, 19/20 something years old and thinks he's really got to stick it on to make it work. That's when you'll find me laying awkwardly on the mat thinking, in a very un-zen like manner: "my turn next mother f*cker."
Then, at that point I have to say I'm not very good Nage either.