Harry,
It's not uncommon in cases like this for the claim of "history" to be made. The fact is, there are many crew who have no history of the type to which I believe you refer but who inevitably cross paths with one of the reporting mindset and end up on the rug if events go a particular way. I know this purser and I sincerely doubt there is "history".
The crew have had it instilled in them that when you have a grievance or when you see a chance to gain ground by someone else's transgression, real or perceived, one should take the opportunity and make a report; and worse - that this is acceptable social behaviour.
Certain cultures in this multi-cultural airline seem more predisposed toward this sort of thing than others. But while some people here have cultural backgrounds in which shameless, gutless stabbing is an everyday part of life, they have also been encouraged by some element of the training experience and/or the management to continue this despicable behaviour rather than dealing with events as adults.
This disjointed lack of cohesion and camaraderie engendering distrust and friction is part of the hidden downside of of EK's >100 mother tongues experience which is advertised to the public.