Its odd as the question was clearly planted - how on earth did the MP know which units to ask the question in? Not exactly household knowledge to ask for defects/50Flight hours is it?
I'm not really sure what it shows - the problem has not got worse, but is a known issue with Nimrods for many years, and is being tracked. Its also clear there have been alot of incidents without serious incident if you see what I mean.
I personally don't suspect any cover up here - its not really part of UK flight safety culture is it? Which, on the whole, I think should still be regarded with respect and integrity, no? (I was last involved in 2003).
Look at the Mk3 Chinooks - left in a shed for years over the faintest whiff of a safety issue (which IMHO is something of a statistical red herring, though I note many a Boscombe purist (with a vested interest mind) would disagree).
On the whole I think its still true that UK engineering culture is one that DOES NOT cut corners on air safety issues and if anything errs on caution and retains a healthly open attitude to understand crashes / human factors issues properly & places correct emphasis on learning from mishaps and not apportioning blame.
(yes, yes noting early Chinook Mk3 architecture decisions etc. - but its STILL in the shed remember, never fully cleared, so the culture persists at the end of the day).
NB Whilst I also believe Mull was a crew issue, not technical, the blot on the above is the decision of the BoI re the crew blame for which I offer no defence - their loss and the knowledge that the Mull incident was down to crew should have been enough to learn from for the wider RAF aircrew community. This incident rather flys in the face of the "no blame" culture which I think still prevails in air accident investigation, or do the learned here think this has really changed?