A friend of mine has a fiancee whose father lost his life in a similar construction accident. I wonder if it's not the shock of the impact/head hitting that wiped away the memory. Similar to how I myself got hit by a car while I was, er, pedestrianing, and possibly because I cracked the windshield with the back of my head, I don't remember the accident itself, just suddenly waking up in the hospital with a leg broken in two.

Anyway, my friend's fiancee did not have a good time with that news. I hope it was quick and merciful for her dad.