The pictures of the main blade at the root end with the pitch change arm look very similar to those in the UK accident that Morane links to - definitely worth a read!
In the UK case, the conclusion is that mast bumping leading to hub failure and blade separation was the cause but the reason for the mast bumping seems to be focused on a harsh cyclic input since there is no evidence of a pushover or turbulence.
What is interesting is that one of the blades flapped so much that it hit the left skid! If that wouldn't damage a blade badly, what would?
Ref the pictures of the Florida blade - was the detached section found with the main blade or not? If it was found with it then it is very unlikely that the separation occurred in the air.
Peter - like you I won't ever get in a R22 again - my last experience of one led to a write-off (dynamic rollover).