The supreme court is made of fallible humans

Have you read https://yalelawjournal.org/forum/customs-immigration-and-rig... ? Quoting from its abstract:

> While the Supreme Court has long recognized a border-search exception to the Fourth Amendment’s warrant requirement, it applies to only two interests: promoting the duty regime and preventing contraband from entering the country; and ensuring that individuals are legally admitted. The government’s recent use of the exception goes substantially beyond these matters.

None of these two interests apply to his targeted search. No duty applies here. By definition, no contraband can exist on an erased phone.

The Supreme Court often disagrees with itself.