While the title of the AP piece would lead you to believe that Meyer and his buddy were guilty of disobeying orders while in a combat zone, the UCMJ does allow a military man/woman to disobey an order that they feel is "unlawful".
October 02, 2006
American Soldiers Are Required to Disobey Unlawful Orders
Jim Macdonald writes:
Making Light: ATTENTION US MILITARY PERSONNEL
: You are not required to obey an unlawful order.
You are required to disobey an unlawful order.
I agree with Meyer's decision to disobey the order NOT to go into the fire zone. When your comrades are pinned down or under attack, to order a warrior to abrogate his reason for being (an unlawful order as far as I am concerned), then it is the responsibility of any military man/woman to make a personal decision to disregard the order.
I applaud the decision to Award this brave Marine the Medal of Honor.
Semper Fi young man ... Semper Fi.