To continue the thread drift. I think JetA_OK has nailed it.
Professional LAMEs only trust their own work, and will scrutinise anyone else's with an intense scrute. That is an essential part of the safety net. As it should be, and thank goodness for it.
Problems arise when industrial stoushes raise emotions. In that environment things are said, which should not be said, and the reputations of other MROs are attacked.
Reality is that, rarely, things get overlooked in any hangar, but the net normally catches them because professional LAMEs only trust their own work. (See above)