I may be wrong but I seem to recall that the experts on the Board Of Inquiry actually declined to label the Chinook pilots as grossly negligent because there wasn't enough evidence to form a clear picture of events leading to the accident.
It was only when the report went up the chain to higher authority that the Board's (expert) opinion was overturned; even though to do so went against the clear guidance in the manuals.
Justice has been done; those that couldn't defend themselves have had their names cleared once and for all.
. .Rgds
Shakey