A person from Southlandia says: ‘It’s uncanny how one can tell a Northlander’s statement – always condescending, never brings facts to the table, and using epithets like “Goonface”.’
The person from Northlandia replies: ‘It’s uncanny how one can tell a Southlander’s statement – always disagreeable, never brings facts to the table, and the only one in the conversation who uses insulting terms like “Goonface”.’
That is, someone makes a statement disparaging someone else. The target of the statement uses the person’s own words and sentence structure against him, changing only details for refutation.
It’s similar to an ad hominem informal fallacy. Instead of refuting someone’s statement logically by offering evidence and arguments that it isn’t true, you point out that the speaker does not live in accordance with the statement.
It sounds like tu quoque. But I think of a ‘you too’ response as more like this [finding an example on the web]:
Peter: “Based on the arguments I have presented, it is evident that it is morally wrong to use animals for food or clothing.”
Bill: “But you are wearing a leather jacket and you have a roast beef sandwich in your hand! How can you say that using animals for food and clothing is wrong!”
In that example, Peter thinks it’s wrong to use animals for food and clothing, and Bill points out that Peter eats meat and wears leather. In the example in the OP, Southlander ascribes certain things to Northlanders. Northlander uses Southlander’s own sentence structure to point out different things that show that Southlander is making an ad hominem attack and to effectively say, ‘You are incorrect. Your statement shows that you are belligerent, are ignorant of the facts in the argument, and ascribe a specific behaviour to your opponents that only you have engaged in.’
So it does sound like an ad hominem tu quoque, but the actual construction seems like it should have a specific name.
It’s sort of a form of metastasis. It does seem like there ought to be a particular term for the parallel substitution, whether as an argument, or to evoke another speaker’s phrasing, or for humor.