IIRC the jujutsu teacher of W.E. Fairbairn (Ozaki?) had a sign that said "Jujutsu and bonesetting". It kinda makes sense for a JJ master to get into that, but maybe it suggests that bonesetting was necessary for JJ injuries. From randori/challenge fights? Maybe, but seeing "old school" JJ videos of dudes doing high amplitude throws on hardwood floors during more choreographed training makes me think it could easily be from non-sparring training as well.
Again I'm going by memory, but it seems that even friendly matches outside the home training hall were quite rough and tumble, and injuries were pretty common. There are references to jujutsu matches from the late Edo Period that sound very much like our pro matches in which participants fought for prizes and went pretty hard.