It's not that he was silent and refused to provide the password. It's that he gave a command to the device to destroy the evidence, so even if they had a fancy zero-day, it was not there to decrypt.

I'm just saying, they're not charging him with silence, which is a right and he is permitted to remain silent. He didn't say, no thank you, to their request for the pin. He didn't claim his right to silence and an attorney. He provided false testimony, in a pin that wasn't the right pin, and that pin destroyed evidence. At least thats how the prosecution is seeing it. You can't argue against a crime you're not charged with. You have to take on the charges directly. How do you argue that it wasn't lying about what the pin was/did? It was. It was a trick pin. It caused a destruction of evidence. It was his intention. Maybe this new charge is less than the charge they would give him if they found the content on the phone, but it's not inaccurate to say he took these actions. If the court agrees he took these actions and that these actions are against some code or another, which seems likely, then they will convict.