GrapheneOS duress PIN could land a man in prison

To be fair, a duress pin is definitely a good thing to have if you’re being mugged, but using it to deliberately destroy data when it’s been seized by a lawful authority is guaranteed to land you in serious trouble pretty much anywhere. Whether the border agents were, in fact, a lawful authority, and whether they had a lawful reason to seize his phone are very different questions.

The much more sensible approach is to either have a separate phobe for travelling, that has nothing you care about on it, or wipe your phone before you travel, and spend a little time building up an innocuous history on it, without putting anything you care about on it. Anything you absolutely must have access to while you’re away can be stored, encrypted, online, and you can remember the details to retrieve it.

The fifth amendment applies to this because he was a US citizen. He had every right to not give them his pin and it would only be destroying evidence if charges had been pressed. In this case some butt hurt border guard just really wanted to look at his vacation pictures or some shit.

The charge wasn’t destruction of evidence, but destruction of property, probably for exactly the reason you mention. He could certainly have arguwd with the agent, but he certainly wouldn’t be getting on the flight if he did, and I suspect he’d be lucky to walk out of the airport without being arrested. As I said in another comment, this isn’t something you can beat at the point of application, it needs to be cut off at the root.