Damn. That reminds me of a motorcycle awareness group that came around to my highschool (like 4 years ago) and told us about how:
One of the motorcycle awareness guys was driving down the interstate, going like 70, and sees the truck in front of him kick up a rock at his face (no helmet). He had a split second that he might have been able to move his head out of the way, but his wife was behind him. SO, he had to take it to the side of the face, chipped his cheekbone, ripped a big chunk out of his cheek, he barely kept control of his bike. Crazy shit.