This reminds me of a time a colleague told me about. Student turned in paper late and at 100%. When they opened the paper, it was simply a Maya Angelou poem in the middle of the page.

Professor failed them for multiple reasons, including the fact that it wasn't only a plagiarized poem, but it had nothing to do with the assignment at all.

Student apparently decided to "fight" this, and so claimed that the poem was her method of expressing her feelings about the paper. When the professor told her, well, they weren't your feelings, because they were copied word-for-word from Maya Angelou, the student looked shocked and proclaimed that, well, whoever this Maya Angelou person was must have clearly copied from her. This was a defense she kept going, all the way through evidence that Maya Angelou wrote the poem before the student was even born.