People can be well-meaning, but have no knowledge. Last year I was in my electric wheelchair (strapped in), but I hit a an unseen ridge at the top of a slope and it tipped the chair backwards. My daughter managed to get her hand under my head as I went backwards, but I felt a jolt in my back and it frightened me..
It was fortunate that my daughter was there, as a concerned by=stander came over suggesting they would help by pulling at one arm whilst someone else pulled at the other in order to get me off my back and out of the wheelchair! My daughter did snap them they did not want me to have dislocated shoulders as well!!!
Few year ago, with three young g.children, one of whom was having a really nasty nose-bleed, one Lady who stopped to 'help', told her to tip her head backwards, to stop the blood going over the furniture (we were in an Ikea store) - I did comment that I was not wishing to have her choking on her own blood.
As someone who now uses mobility scooter and/or electric wheelchair anytime I am out, I am still horrified as to how many places just pay lip service to the idea of being accessible, and how many people still have the 'Does he take sugar?' approach to people in wheelchairs. It is my back that is the problem, not my brains.