In some cases it's the intent that matters, but the law often tries to avoid questions about actual intent because that's too difficult to figure out. Instead the question might hinge on what a reasonable person would have thought, or what the victim actually thought.

Of course the law tries to avoid it. But that’s sometimes impossible, thus disagreements and trials and judges and whatnot.

It’s not like ambiguity causes everything to crash. It just requires judgement that usually gets settled before it gets to court.