Oh boy, nightmare for sure!
I posted once about deciding not to tie in with my lanyard because of the possibility of something going wrong with a spear cut, it did and had I been tied in twice, I shudder to think of the consequenses (neck, back etc.), instead I just got knocked off my perch, firm, high main tie in swung me gently out of the area upside down...
But hey, who's to tell, we can't always anticipate or foresee every possibility, so that 'bit' breaking off saved his butt, if not his life...AMEN!
The gut wrenching moment of realizing all that weight is on your climb line, with you in the middle as the weak point, oy...!
Super glad he's ok.