Originally Posted by
ethicalconundrum
Since it was coming out of mx, if not a failure of the strap pack, could be incorrect asm after stage check, or left loose, or something like that. A dual failure would indicate that the problem was not related to one blade asm, but covered both blades being affected. It would be possible for the first failure to lead to the second failure, but then the other two blades seemed to stay on the hub all the way down.
After one comes off for any reason, the rest can be a crap shoot.