I suspect this bloke will be dismissed as quickly and as painlessly as possible to save further embarrassment. Jail time is highly unlikely and, no matter what the officers on the court-marital believe, the word from on high will be "bury this quickly".
Siegfried Sassoon refined his anti-war stance in later life, after the Second World War, and concluded that he may have been wrong.
With regard to the officer at the source of the current controversy, I completely agree with his views regarding the legality of the 2003 outing but disagree with his decision to refuse this order as the order is legitimate because of the post-war UN resolution and the position of the Iraqi government.