I once told my Stn Cdr to his face during my ACR debrief that I didn't believe him when he told me the RAF had a "just culture" ( it was the mid 90s so not sure if the actual phrase "Just Culture" had been invented but that's what he was talking about), he took it rather well to be honest.
There had been a recent incident where someone had indeed been f*cked over by the system, including that Stn Cdr, and I merely pointed out that "the system" can talk the talk all it likes, but all that can be undone by a single poor decision, and that there was just such an undercurrent among the JO aircrew on his Stn. The actual incident was never mentioned, but he knew what I meant.
Still surprised I got away with being quite so blunt.