Well, you know Guys, we Mediterranean people tend to add a little spice to our words sometimes
you would however be surprised how often such things did happen.
I agree with both of you, Peter and Erik. I would like just to give some other example of situations where Uke could be hurt by Sensei.
I have occasionally seen some Yudansha challenge their Sensei when they are called to demonstrate a technique: They might resist the technique, be uncooperative, or respond in a non conventional way. In such cases, I have seen the Sensei rightfully put some extra pressure on a Nikkyo, or throw a little harder than usual, in a kind of punishment, or reward, for the challenge. But things can go wrong, and a little extra pressure can be enough to brake a wrist or a forearm.
I believe it is the Yudansha duty to keep their Sensei's technique sharp and effective, despite the promise of a painful but instructive outcome.