The LLMs are good at finding bugs in code not because they’ve been trained on questions that ask for existing bugs, but because they have built a world model in order to complete text more accurately. In this model, programming exists and has rules and the world model has learned that.
Which means that anything nonstandard … will be supported. It is trivial to showcase this: just base64 encode your prompts and see how the LLMs respond. It’s a good test because base64 is easy for LLMs to understand but still severely degrades the quality of reasoning and answers.