Actually I wasn't intentionally wrong. Just something I missed when I was proofreading. I fixed a few others including one where I had willing when it should have said unwilling.
It should say something like "Can you prove the intent? If not, then you cannot prove it was a lie."
Why would anyone ever be intentionally wrong, eh? ;)
Only example I can think of is if they are trolling or baiting you. :)
It was a rhetorical question (but good answer, all the same - I can't think of any other reason).