Well, I really am not a turner, but I am making a shaving horse for a friend, and after riving some ash blanks out of air dried billets, I was spinning a 2 x 2 x 24" piece of ash rather too fast.
Flew off and hit me in the face shield and face. All I can say is I'm glad I had the shield on, because the damage would no doubt have been worse. Most of the force was on my mouth. Both lips are cut on the inside, but not requiring sutures. And one front tooth isn't feeling great, but fortunately did not get broken or knocked out. My lips are pretty swollen too.
I think my mistakes were:
not fully squaring off the end that was held by the live center.
spinning too fast
applying too much force
turning anything big enough to hurt me
Here's what the face shield looks like. It has a dent where the piece hit. The red stuff is on the inside.