MiniMatt

The highway code is not the law. The highway code is referenced by judges when applying and indeed creating by precedent, common law, such that common law will frequently mirror the highway code, but the highway code itself is not law and hence obeying or disobeying it in itself is neither legal or illegal.

As for your example, I'm sure (assuming your description is accurate and truthful) that falls within the boundaries of common sense, common sense of course being that which drives the creation and application of common law.