Yes, the proper definition of "code" here is "something the author expects to be executed as instructions to a computer" - which inherently requires Theory of Mind to identify.
Nah, you get around needing an explicit theory of mind with the fictive "reasonable person." Most systems of criminal law place a lot of importance on both mens rea and intent.
Mens Rea is exactly why you need Theory of Mind. One can't judge intent without it. The point is that some naive mechanistic definition like "Structured information" that another commenter suggested isn't going to fit the bill. It is the intent to have the message be maliciously executed that needs adjudication, and you need a human that can exercise theory of mind to be able to do that. One can't do it with a regex, for example.
Especially in the coming era of natural language interfaces, the only difference between code and other language is how it is intended to be used.
You might have something like a theory of mind, but it would be a generalized theory of mind that provides you with conclusions like "a reasonable person would probably not perform SomeAction unless they intended SomeConsequence". You don't actually need a theory of mind for the specific accused person. They could be a p-zombie, and that won't change the legal process.