if that would indeed be what the immigrations officer said, then taking the advice would be an reasonable way forward. Although even then, asking for potential different ways here in the group could reveal something (we know it doesn't, but we know the answer to the question; there certainly are situations where immigrations doesn't tell you the whole story).
But now that they are so wrong, wouldn't you agree that his seeking for confirmation in a group where people know this was useful?
Unfortunately the immigrations officers at the airport misinformed you. You cannot exchange stamps with immigrations, neither at the airport nor locally. You really need to leave the country to activate the DTV.
sorry sir, I'm not talking BS there, but you are. Immigrations offices aren't even dealing with visas in the first place. You're speaking with way too much confidence there.
I've already told you where the best place for advice is. It's here. For specific visa questions, the embassy is the go to place. Not immigrations.
What a bunch of crap. The immigrations office cannot give him anything useful. Here, on the other hand, is where you can find people who know the ins and outs and can think along. If that's not you, perfectly fine, but don't send people to places that won't get them and further please.