Theoldtimer - strangely enough, just because I fly the Sea King doesn't mean I am ignorant of composite materials - I went on a very interesting university course a few years ago all about composite materials in aerospace structures including visits to industry to see the production and autoclave process in action. I did learn that whilst composite materials are generally lighter and stronger (in compression) than aluminium, any repair process, unless perfectly carried out in ideal conditions, is susceptible to cracking, debonding and delamination and that impact damage to such structures is usually fairly terminal since composites tend to crack and shatter instead of dent and deform like aluminium.
So, since AW are clearly well aware of such issues, one would have thought that the highest level of scrutiny would have been applied to a repair carried out on a vital structure like the tail boom which had suffered a previous tail strike. This clearly did not happen or the tail structure would not have collapsed in the way the pictures show - hence my comment 'WTF' whilst not being constructive is, I think, appropriate since the failure really should not have happened.