Demand an attorney, and remain silent until your attorney advises you to speak.
He did so REPEATEDLY.
That is where they have him.
No they don't. The thing is, even without the constitution there's many reasons this case will fail. For one, it's not automatically obstructing law enforcement by destroying something.
To prove their case the government needs to prove the person was authorised to search and seize the particular property, and saying "We're the police" isn't sufficient. Also particular property means they need to have a reasonable suspicion on what was destroyed.
Secondly the *defendant* needs to destroy the evidence, he didn't even touch his phone.
Oh and the big one, the obstruction only applies if the person prevents "lawful authority" from siezing evidence. There's existing case law that shows this only applies when executing a warrant. In order to do that it ties into the first point, you need to know what you're trying to take into possession.
So the government needs to argue that they were taking into possession data they knew existed, not just a phone. Good luck to them. This is a hell of an uphill battle, and a complex case to prove, and it's worth noting that the people who need to do this are the same people who both misspelled the name of the country "Untied States" as well as listed the wrong agency "Customs and Border Patrol" (instead of Customs and Border Protection) being obstructed on their official court docket. I wouldn't trust these people to get a McDonalds order right let alone be able to argue a legal case.