External review letters for tenure cases, like recommendation letters more generally, aren’t usually public, so who knows what juicy bits are in there that will never see the light of day? Here is a line from a letter which I promise is genuine:
[Prof. X] is too bold for [his/her] rank, and uses the first person pronoun too freely for a junior scholar.
Not a physicist, not anyone at Caltech or anywhere else I have been affiliated with, so don’t even try to guess. But I’d be tickled to get such a line. (The candidate received otherwise uniformly positive reviews, and was unanimously approved.)