Refusing an ambiguously-lawful order would, under that source, trigger a prosecution or nonjudicial punishment under UCMJ Article 92 - Failure to obey a lawful order or general order. And it would need to be determined at trial and/or on appeal whether the order was lawful, because Article 92 requires the Government to plead/prove four things:

- That a member of the armed forces issued a certain lawful order;

- That the accused had knowledge of the order; and

- That the accused had a duty to obey the order; and

- That the accused failed to obey the order.

If the order is deemed unlawful by the military judge or appellate court, the case must be dismissed, because the Government has failed to allege an offense.

Ah, that clarifies things. Thanks!