To use a less trite example, I'd probably find some case where a word or name can have different meanings in different contexts, and how that can be confusing rather than clarifying without further documentation or knowledge of the problem space.

Really though, any bug in the code you write is a deviation between intent and implementation. That's why documentation can be a useful supplement to code. If you haven't, take a look at the underhanded C contests- there's some fantastically good old gems in there that demonstrate how a plain reading of the code may not convey intent correctly.

The winner of this contest might be a good example: https://www.underhanded-c.org/_page_id_26.html