Bgi,
I've had that happen. In defense of the parties involved, it was purely an accident. Buddy started his plane (pointed in a safe direction) and while moving around to the back of his plane tripped over a cord. Well, he bumped his throttle wide open and bumped the plane around towards me (wide open). Funny thing was that I was trying to get out of the way of the prop and try to catch the plane at the same time so it wouldn't hit my own planes!!!! lol. Luckily I caught the wing of the plane at the same time as he cut the throttle, so all ended well. But I can tell you that both him and I had a brown streak down the back of our pants after it was all over!!!!

point is, be prepared because anything can happen (and usually does) out at the field.