Nah, it doesn’t change anything. The statute says

Whoever, before, during, or after any search for or seizure of property by any person authorized to make such search or seizure, knowingly destroys, damages, wastes, disposes of, transfers, or otherwise takes any action, or knowingly attempts to destroy, damage, waste, dispose of, transfer, or otherwise take any action, for the purpose of preventing or impairing the Government’s lawful authority to take such property into its custody or control or to continue holding such property under its lawful custody and control, shall be fined under this title or imprisoned not more than 5 years, or both.

It’s clear that if he intended to wipe the phone and told the officer a password which would erase the contents, he “knowingly took an action for the purpose of preventing the Government’s lawful authority to take such property into its custody”.