Re: I still get wound up...
Whilst you are correct in saying that, you still cannot trespass with permission, civil matter or not. It's logically not possible.
"Do you have permission to trespass on this land?" See? It's one of those questions where the English "Yes/No" response is severely lacking. The Japanese have a response though, Mu!
Mind you, answering a question like that in a manner that sounds like you are pretending to be a cow is likely to get you shot.