Selectively detaining this guy, likely overreach.
Trying to get his phone's unlock code to go on a fishing expedition for whatever they can find, absolutely overreach.
But this guy catching felony charges for giving federal border police a duress PIN to wipe his phone when they asked for an unlock PIN? Not actually overreach.
You have the right to remain silent, not to lie to the police when detained (18 USC § 1001, and many state-level laws to the same effect also exist). Our justice system could not function if people had a right to lie to the police. Once you are detained, whether or not that detention is eventually determined to be lawful, destroying or disposing of your possessions to prevent police from accessing them is also generally a crime.
You fight abuses later, in court. Or, if you're going to use a duress PIN in the moment, you accept the legal consequences.
And yes, giving a duress PIN to wipe a phone when asked for an unlock PIN is a lie which may result in destruction of evidence. And no, the law does not care about "I'm not touching you"-level rationalizations of whether something is a lie or whether it was technically the police who entered the code to wipe the phone. Proximate cause is a longstanding legal concept.