Aside from Harry's parents, there was only one "unrealistic" adult so far (by Ch6), McGonagall, who assumed Harry might have been abused. Her tolerance is reasonable.

It's irrelevant, though. Harry is behaving strangely, and you assume it's bad writing. I guess, since you have read some fanfiction ("OOC is irritating to me"), you aquired a useful heuristic for filtering out bad fanfic; it's just that it is bound to give some false positives.