I agree on the "default position", though I cannot see anything so inappropriate to justify a HR call or a complain to the (official or unofficial) company list, at the very most a comment like that could have provoked some snappy response and an immediate - on the spot - clarification between the parties, at least between "normal" (adult) people. That would be a "normal" reaction as I see it, saying nothing then writing to the list a complain seems to me like the act of someone that either has experienced much more serious "name calling" (or some other untold offence) or that is a tad bit oversensitive.

Most probably normality - like beauty - is in the eye of the beholder.