Been there and done that . . . (2006)
Felling a tree (not large just 12-14" DBH), - I was pulling the saw out of the cut as the tree was just beginning to fall, a dead limb came down and knocked the saw out of my hands. It tore off and broke the air filter cover and bent the bar on the chainsaw.
I was not hurt except for my hands being wrenched, but the event really scared me. I didn't have a safety helmet but the limb would have probably done more harm than a knot on the head if I had been hit with the limb?