If that's true, I suspect it's because the good Major is about to be reassigned to a slot that allows him to learn first-hand the joys of the military justice system.
He can't possibly be subject to any UCMJ action until tomorrow, when he is ordered onto active duty. Only if he then "refused to go" would he have committed an infraction under the UCMJ.
No matter what you might think, reservists are civilians for almost all purposes. They can't resign after receiving activation or movement orders, but are still civilians until the effective date of such orders.