Ah -- IME people usually start a sentence with "in the nicest possible way" when they're couching something mean is all. Often it's even sarcastic, and the meanness isn't even meant to be couched, so I wasn't sure how to read it

Agreed, the default connotation / reading of this phrase implies a snide attitude.

Ironically, I went back and added it because I thought the comment sounded a little bit unfriendly on a first pass. Mission failed.