When I was fifteen, I was walking to a friend’s house to drop off a couple of kittens. There’s a place in my hometown where two roads come together very much like a lowercase “y.” On the main road was a motorcyclist in a helmet and leathers, doing at or slightly below the speed limit, doing everything right. On the short end of that y was a dude in an SUV on his cell phone. (Note for users born after roughly 1994: Bluetooth did not yet exist and in-dash hands-free calling existed only for very wealthy people. You held your phone to your head or you didn’t talk.)
Yeah, you know where this is going, don’t you?
The motorcyclist went flying as the SUV blew past its stop sign. He hit the ground in front of the library (going straight between trees to land on lawn, thank g-d) and bounced.
Now in my hometown it’s actually part of the ninth-grade curriculum to get Red Cross-certified for first aid, because it’s rural and in some places it can take up to an hour for an ambulance to reach you if the weather is bad. The three adults at the scene—not including the SUV driver, who was an asshole from out of town—all looked at me. I was the one with the most recent training, so I was the one nominated.
The outside of this dude’s helmet was shredded from rock and pure speed of impact. I didn’t dare remove it because of the risk his spine might be broken, but with help from one of the adults I did get the visor open so he could get some air, and I set about tourniqueting his leg. In the time it took us all to see the impact, register that that really just happened, and me to set down the kittens and run across a two-lane road, he’d started to bleed through his jeans.
I did not tourniquet correctly, and an EMT had to fix it when they arrived on-site. What I did do was keep the guy from bleeding out, but he still lost his leg. Between the botched tourniquet and the injuries caused by impact, there was just too much damage. There might not have been any saving the leg even if I’d gotten it 100% right, but on the whole, losing his leg was better than losing his life, which is what would have happened had I made no attempt at all.
But if he hadn’t had a helmet on, I wouldn’t have had the chance to fuck up the tourniquet. They would have been washing his face out of the library lawn, and possibly his brains, too.
The fact the motorcyclist survived began with his decision to choose a good helmet with a full-face shield and appropriate riding leathers and denims. It did not protect him from 100% of injury but it did make sure he’d live.
The moral of this story: keep your eyes on the road, take a first-aid class, and wear your fucking PPE. Physics doesn’t care if the other guy was at fault.