Thanks for the inside baseball on how the military treats reserve officers.
I wonder, however, if the Major was not already considered to be on Active Duty since he had volunteered to deploy with a unit as an “augmentee”. It may well be that this unit’s departure date is imminent and he is already training with that unit full-time. The stories I’ve seen don’t yet get into that amount of detail.
This is a cautionary tail about a civilian lawyer attempting to navigate the military justice system. I’d feel a whole lot better about the Major’s case if he were represented for a former JAG officer or a lawyer with prior military experience.
As a clarification, this is how the military treats reserve officer that are non-ob. If this was an involuntary deployment of a obligated officer, I suspect the case's outcome would have been MUCH different.
As for your question about when he was on active duty; He would have been on active duty when his orders said he was on active duty, and not a moment before. There's plenty of cases where reservists have been in DUI accidents on the way to either a reserve drill or ATD or even a deployment. They won't face a court-martial for the DUI, but they could face several other charges relating to their unauthorized absence as a result of the DUI.
Lastly, I think you make an excellent point about civilian lawyers navigating the UCMJ, especially those with no JAG experience and particularly one like Cook's attorney who in fact has very limited ligation experience in total. Civilian laws are created to protect civilians. Military laws and regulations are there to protect the military. And experienced military jurist never forgets it.