I think one needs to understand that their is a colossal difference between Gross Negligence which is culpable and Pilot/Crew Error which is simply human nature. It's also why there was such a burden of proof required for one that was not required for the other.
I don't believe anyone with an actual vested interest in the finding would balk at the possibility of Aircrew Error in this case. However, the length of this very thread attests to the general feeling that Gross Negligence was utterly uncalled for and, demonstrably, in contravention of the regulations at the time.