I don't think the difference between him physically triggering the wipe and him giving them the code that triggered the wipe would have much effect from a legal point of view. In both cases he deliberately took an action he knew would lead to the destruction of the data. I think his defense's approach of challenging the legality of the stop is probably much safer.

I suspect that the prosecution would like to set precedent that you can't claim to be under duress when a lawful authority is performing a search, so the defence staying away from that area is probably a good idea.