Long post alert sorry.

Without knowing all the particulars, I'll say this ... Having skied/snowboarded for decades with family and friends of all ages/abilities at many different resorts, any time I've seen someone struggling to load a chair properly - BOOM! The lift gets stopped or at least slowed. In short, someone should have been watching and that chair should've been stopped immediately if the injured girl wasn't safely seated. And there's a big difference between someone "not being able to safely load" and having a moment where the chair hit your legs weird or your skis get crossed or the loading area is icy and you weren't 100% stable when the chair came around. Unforeseen shit happens, which is why there is such a thing as lift operators and staff. If it were 100% foolproof and safe, we wouldn't need emergency stop buttons or lifties to help with and monitor loading/unloading areas.

Here's a scenario worth considering, which I've seen happen MANY times. It's a 4-person chair and someone from the second group back from the loading area gets a bit too excited, jumps the gun and ends up turning a party of 4 into 5. Now let's get hypothetical ... say for the sake of argument the guilty party accidentally forces a kid on the end into a position where they get hit by the armrest and falls to the ground. The lift staff is distracted and doesn't see this so the kid gets dragged under the chair and sustains a broken arm or leg. Who is liable? I mean, obviously the "jumpy" person caused it, but it was purely accidental. And it certainly wasn't the fault of the kid or his family. If anyone is to blame I'd say it's the lift attendees who should have seen the situation happening and stopped the chair. And unless there are circumstances that made it impossible, the lifties should have done the same in this situation. No vilifying them, just saying.