This is one of those things the other comment calling the law "non-autistic" is referring to. In the eyes of 99% of people, it's functionally the same thing. "Well teeeecccchhhhnicallyyyyyyyy I still have the data..." isn't going to make the security workers at the airport slap their heads and say "damn, he really got us! Go on through!"
No. They'll arrest you just the same for obstructing their search. Then they'll keep you in detention for a long time while you say "I can unlock it for you! You just have to let me out!"
You can pretend you have leverage and say they need to cooperate with you. But once you're detained, police and prosecutors don't really care about cooperation anymore. Their idea of cooperation is you giving them what they want immediately without question. You're made into an example if you don't abide.
You are incorrect, US border patrol can not arrest you for refusing to decrypt your phone (if you are a citizen). It is not considered obstructing a search to refuse to provide a password. This is not "autistic" speculation about legal technicalities, there are many many examples which support this. The worst they can do is seize the device.
You're free to test them. See what they do when you say "it's not deleted. It's just inaccessible until I cooperate." Because it's identical in their eyes. People who confidently say "the government can't do that" rarely have a good day. They end up sharing a cell with the person in the article this discussion is about.
And we're living in an era where immigration enforcement can shoot Americans without penalty. It just makes the claims that the government can't arrest someone come across as naive.
I have tested them, that's what I'm saying! The belief that the authorities are completely unrestrained in their power serves authoritarianism. Creating this belief is in fact a major priority for the current regime.
This is not to say that things aren't bad, or abuses never happen. But if people fail to exercise the actual power and rights they do have, under a mistaken belief that they have no power and no rights, then that will become a self-fulfilling prophecy.
That's precisely what happens in totalitarian states, which the USA has been for a while now, but the propaganda keeps telling how much freedom there is so people didn't even notice.