I think many of us have done it a time or two. I have to be careful when on the range shooting a heavy kicker. When hunting I am more erect and have the gun shouldered better than shooting from a bench. I did it once with my ML with magnum loads (3) 50 gr pellets and another time with a shotgun with a scope that had poor eye relief. Both times I was lucky and only made a mark not the "idiot cut". Now that it happened to you it is easy to laugh at the next guy.