hsimmons et al,
The same thing happened to me but with a smaller engine, a Saito .56. 16 stitches (6 through the fingernail) on two fingers.

My accident happened the same way (accidentally hit the throttle) but my plane WAS in a tie-down...

My mistake was that there was room for the plane to come about 6" foreward, and that's what hit me.

Just a word to the wise... don't be complacent just because you have your plane tied down or in a 'stooge'.... make sure that the plane is as far forward as it will go BEFORE you start that engine, so that it doesn't jump those remaining few inches at you...

I know that it sounds fundamental, but that was the one and only time that I didn't check, and look what happened... Just something for you to watch out for, for yourself and for your flying buddy...

Hopefully, I added something meaningful to the discussion.

Bob