"A friend of mine is a non-native English speaker. He teaches at an elementary school and works with ‘English as a second language’ students. He casually mentioned that he always tells his students to take a ‘horse bath’ in the bathroom sink after recess if needed. He was traumatized when I told him that he’d misheard that phrase for his entire adult life."
The censor hits any substring, rather than trying to heuristically guess whether the substring is being used as a slur or not, it assumes users are smart enough to pick up on the context.
He thought a "horse bath" was just a quick rinse off in the sink. He was inadvertently teaching ESL elementary school kids the phrase "whore's bath" which, while it is technically just a quick rinse in the sink, there is definitely different connotation.