To everyone who thinks this is somehow a violation of rights: if you were being questioned by border officers, and were asked 'Sir could you please open your suitcase', and you pressed a button that caused it to burst into flames, there isn't a country in the entire world that wouldn't arrest you on the spot. Why would 'wipe a phone when officer requests it opened' be treated any differently? Suspicious behaviour is treated as suspicious by normal people.

It doesn't sound like this person pressed any buttons. They were pressured to provide a PIN or be delayed and further harassed. They obliged, and agents decided to enter it to attempt a warrantless search of the phone.

It's not stated, but probably we can assume the person didn't ask for his phone to be searched - probably he asked NOT for it to be searched, at least based on his multiple requests to talk to his lawyer.

Considering those factors, I'd say border patrol is more responsible for wiping the phone than the person.

Right, but by that rationale, it’s also suspicious to say “no” when they ask if they can open your suitcase. Or decline to tell them where the key is. Or ask to speak to your lawyer first. Or refuse to tell them what is in the suitcase. Or lock the suitcase in the first place. And I want to live in a society where those behaviors are protected.

(1password has a “traveling” mode that wipes it of sensitive passwords before going across borders. Is that suspicious? Should it be criminalized?)

Yes, they would be rightfully arrested for setting off an explosive device in an airport. This analogy ... isn't great.

material =/= information.

Are we supposed to live in a world where if I'm crossing a border I must give access to all of my information? That's absurd and more equivalent to a full brain/memory scan than a suitcase search from your example. This is dystopian in every sense of the word.