I think they confused "slur" with "swear" and are referring to the f-bomb on the last page. It might have set off some alarms as a previous translator had a penchant for having Ikezawa swear every other page (notably calling Eguchi "that cunt") regardless of contextual suitability and responded...
Right? My internal monologue for that scene was "Nobody takes their bra off by the cups like that... has sensei never seeWHAT is she doing with that razor there?!"
Did someone on the team just recently learn the word "cunt"? There have been two instances of it in the last three chapters that didn't suit the original Japanese, the characters, or the context. Even in British-English, which uses it far more casually than American-English, this usage wasn't...