It was Michael C. and my boss from work was belaying. Michael C hooked himself to his left axe (=anchor), placed a screw, my boss lowered him down, and then he took my crampon, and I was stuck standing in the ice on 1 foot and freezing...:)
It was interesting to see how cool and calm he was about it.
That's gotta be scary. A similar thing happened to a friend several years ago. He was wearing Grivel Rambo crampons, an older model with lots of nuts and bolts. He hadn't checked that they were tight, and I guess some of them were loose.
About 15' from the top of the pitch he noticed that it was only the safety strap that was keeping one of his crampons on .. he finished leading the pitch though =:-O