Right then, this guy Ben that craigxxl has linked to – looking at his injury it looks to me that the actual injury he suffered was caused by his helmet. The shape of the ‘tear’ in his scalp is the shape of the pressure the helmet would exert in a crash.
That’s not to say the helmet didn’t help, but you cannot say for certain that his injuries would be worse without the helmet. The only thing you can say for certain is that they would be different. Chances are the outcome would be much the same I imagine.
If a similar injury was shown from a rider not wearing a helmet, presumably those who advocate wearing a helmet would use it as an argument to do so…
For what its worth I think its a good thing that people can choose to wear a helmet if they want. Its also a good thing if people can choose not to wear one. What should never happen is for people to be obliged to wear one.