Not if it shows he was not born in the US.
The Manual for Courts Martial specificially indicates that the authority of the order giver is a factor in the lawfulness of the order.
Even if it shows that. He missed movement and he refused to obey the orders of his brigade commander. He can still be convicted of both.
The Manual for Courts Martial specificially indicates that the authority of the order giver is a factor in the lawfulness of the order.
And the order giver was his brigade commander.