First off, there aren't a bunch of ridiculous comments. Most posters are very supportive and even those that are critical have good points to make. Secondly, the passenger has no options in what gear they choose to wear or not wear. That is solely up to the owner/rider of the bike. If the passenger chooses not to wear the gear then they don't get on the back, period. Third, to say it was an accident and that he did nothing wrong is just silly. It was an incident that was the result of two bad decisions, not wearing proper gear and accelerating too hard for the passenger on the back whether they were expecting it or not.
Everybody does stupid things at one point whether its in a car or on a bike and we all learn from them. I remember showing off the power of my GS750ES to a passenger and finding out on a high speed corner that this guy had no experience on the back of a bike and was counterleaning in the corner....it was all I could do to get the bike leaned over and avoid drifting right into the curb and crashing....scared the crap out of me and I never did that again! This whole story reminds me of why I never ride on the back of anyone elses bike. I just don't trust the pilot enough.
I give you a lot of credit for posting this and I really feel for you and your daughter in relation to her injuries. I hope she heals up soon.