I agree, the lack data really makes it _impossible_ to decide who is in the right here. I propose an experiment: go ram your head into a brick wall with and without a helmet. (To reduce the variance of your estimate, you'll probably want to perform ~10ish trials.) Then report back, and we'll finally get to the bottom of the extremely nagging and tough to judge question of whether wearing a helmet is an improvement when it comes to smashing one's skull into inanimate objects.