True, but it is worse than that. If you call the tax office and ask them direct questions about doing business abroad then even they still give you an answer with a disclaimer that it might not be correct.
My flatmate is an international sales tax expert. I helped her debug hairy tax problems a couple times - not that I have any expert knowledge of tax laws, I was mostly rubber-ducking her - it sounds like an absolute clusterfuck.
Like other domains of law it's not always clear cut, it wasn't like, yeah Alice Inc. owes exactly X% taxes because of law A, it was like, we can argue that Alice Inc. owes X% based on laws A and B, C, but the tax authority could argue they owe Y% based on an argument that actually, laws B, D, and E apply to their case, which we would counter-argue with, etc., etc., etc.
So I'm not surprised the tax office wouldn't give straight answers; even they may not know how a court would rule depending on the specifics of the case.
