Maybe less than it seems:
http://www.foxnews.com/politics/2009/07/15/soldier-claims-obama-isnt-legal-president-doesnt-deploy/
“”Cook is an “individual mobilization augmentee,” or a reserve soldier assigned to an active component unit for duty, the newspaper said. He submitted a formal written request to Human Resources Command-St. Louis on May 8 volunteering to serve one year in Afghanistan.
...
Incidentally, Cook did not have to hire a lawyer to refuse his orders to go to Afghanistan. As a reserve soldier and volunteer, he has the right to revoke his deployment orders.””
I read that in the link you provided, I don't think it is true. Even as a reservist you can not pick and choose your orders. You can certainly request a specific assignment, but you can't have orders in hand and then decide you don't like them. I may be wrong, but when I was in the service we had reservist that served along side us and they were subject to the same rules we were; And I sure as hell could not get orders changed just because I did not like them. Otherwise I would not have spent 4 years in Altus Oklahoma.
Hang on here. You said that because he “volunteered” to go to Afghanistan he can then “un volunteer”? Doesn’t sound right since it would mean an individual who volunteers to join the military can at any time do the same thing and “un volunteer”. Besides if you were right I believe the DoD would have said exactly that.
Reserve sokdiers can get orders revoked?
—As a reserve soldier and volunteer, he has the right to revoke his deployment orders.””—
do tell.
“In all cases, whether Guard or Reserve, members ordered to Extended Active Duty (EAD) — such as for a deployment to Iraq or Afghanistan — are subject to the UCMJ. Guard and Reserve members who refuse or fail to comply with EAD orders, or go absent while on EAD are treated the exact same way as active duty members who go AWOL.”
http://usmilitary.about.com/od/justicelawlegislation/a/awol8.htm
That's terrible that he lost his legs. Was it during battle? ;)