I watched my high school best friend die in front of me when his clutch cable on his kawasaki snapped and caused the bike to lurch forward just enough for an Oldsmobile to center punch him and kill him instantly. He had both feet on the ground, and the front hand brake didn't keep the bike from being pushed forward into the traffic lane.
I have also been rear ended (3) times while on motorcycles! A drunk chick rear ended my Goldwing while I was in the first position at a traffic light at the end of the freeway off ramp. Having my foot on the rear brake, and my hand on the front brake, crumpled the rear of the bike, but didn't push be far enough to reach the traffic lane. Second time, a young girl was on her cell phone, and ran into the rear of ST1100 and pushed me forward enough to just tap the bumper of the car in front of me ( I was almost a full bike length back from this car). Foot on brake saved me again. The last time (hopefully the last time) I was stopped in the third position at a red light, on my GL1500 Goldwing, when a Stolen Honda Acura, fleeing the police, smashed into me without any skid marks, brake lights, etc. They estimated the kids in the car were doing 50+ mph at the time of impact! This one completely crushed the Goldwing, knocked the engine out of the frame, sheared the exhaust off the motor, and tossed me over the car in front of me, and I landed on the truck of the car that was in front of him. I was taken by ambulance to hospital. Nothing would have helped me that time. Oh yeah, the three kids in the car, got away.