I'm sorry to hear about your friend, and hope they recover well.

Something I think a lot about when it comes to e-bikes, is the level of protective gear people feel they ought to wear on "a bike". Not all cyclists even wear helmets (obviously bad), but in addition to a helmet, on an e-bike you really ought to be wearing elbow and knee protection, purely because of the speed involved.

However, my sense is that people (a) don't think about that at all because they think of it as just like a bicycle, or (b) don't want travel with all of that extra gear. They want to treat an e-bike like a bicycle, when it is something much more.

I say all of this as a cyclist (non-e-bike) and rollerblader. On my bicycle I will just wear a helmet, but because of the particulars of rollerblading, I always wear elbow-pads and knee-pads. Differing circumstances require different adaptations.