Something that is important to note here is that the throttle was ACCIDENTALLY pushed forward.

I know that I take many precautions around a running engine, but I also know that I have had several times when that throttle stick can get bumped - this seems especially so for the guys who use neck straps.

So aside from being cautious as to keeping body parts away from the prop, also keep in mind where your throttle stick is, AND your antenna! (I've seen a few people bend over and stick the antenna in a prop)