I think people should know where all their body parts are in relation to hazardous objects. Just went thru this yesterday. My 10yr old son was cutting a slice of banana bread with the knife coming down over his crossed wrists.(no injury) I showed him how to turn the loaf around and cut away from his body parts.
Leaving a hitch attached to a vehicle is purely a personal preference. I see no fault of the vehicle owner if someone walks into a part of it. Blaming someone else for one's inattention seems to be a common practice these days. Personal responsibility should be taught in school as the 4th R. Reading, Riting, Rithmatic, and Responsibility.
I hope your wife has a speedy recovery.