Nasty!
Bit disappointed that the rider didn't STOP to make sure the guy was ok - adrenaline can make one think he's ok, when later the true nature of his injuries becomes apparent.
Sure, the hooked rider SAID he was ok, but his neck took the brunt of dragging his entire body along, and the weight of supporting it too.
I wouldn't be at all surprised if after the adrenaline dump, he was worse for wear....
Cheers,
Rick