That you are not a helicopter man is obvious from your comments.
If you are interested and have time on your hands, read back over this and the archived thread.
No, they could not climb, as the Mk2 Chinook had an icing clearance (sic) of +4 Degrees C.
Whatever happened, and as Brian points out, even negligence is not ruled out by the campaign, it has to be proven beyond any doubt whatsoever for the slur of Gross Negligence on your colleagues to stand.
With no evidence either way, it is an unsustainable finding.