That thread title must have snuck under the limit by a whisker. A Taiwanese person being racist to a Korean person, not something you see everyday, at least not in the US news.
I'm not convinced that telling someone, who themselves admit they have a heavy accent, that they kind of need an interpreter to be understood, is 'mocking'. I mean, I don't speak Spanish and I worked for years as an installer for Bellsouth in South Florida and I would often find myself in a situation where I would need an interpreter to explain what someone wanted me to do in their home. So, I have to say that I didn't see it as 'offensive mocking' when I would hold up my hands and try to communicate to the Spanish speaker "No comprende. Neccesito interprete."
Usually they'd call a Spanish speaking friend or get one of their children to interpret where they wanted a jack installed. Maybe, I haven't heard the woman speak, but it may be true that just maybe she does need an interpreter to help English speakers understand all that she says clearly. I mean, I could often catch a word or two and know what those few words meant, but that hardly gave me confidence that I understood an entire conversation. Just maybe?