The relatives of the deceased can sue for libel if it can be proved that defamation of the dead affects the relatives' own reputation as well.
Some people need to calm down a bit. No reference has been made to the rellies reputation or specifically that of the business, just to the late MW.
However if any of the rellies were legally involved in the helicopters operation and objected to that comment, then they too in the defence against that comment, would have to answer for the 'discrepancies', eg ex mil unservicable items fitted to the aircraft and no records of time lifed component useage over three years. Whilst the comment may seem harsh, the definition of it is 'dishonest', which could reasonably be applied to fitting unserviceable bits I'd suggest. They'd also be up against 'fair comment' i.e. if the statement was a view that a reasonable person could have held.
Regarding log filling, tech or otherwise, I don't feel there's any excuse for not doing so at the end of the day, even if its a busy multi sector day. Pencil and a reporters notebook kept in the cockpit, its not that difficult is it?