No. A video of a Marine shooting himself in the foot would be grounds for being called a dumbass. The membership in the armed forces isn't a blanket protection from criticism for individual acts of Darwinian gene pool cleansing, nor should it be. The rule is that you can't attack the person for simply being in the military. Calling a DEA agent a schmuck for shooting himself in the foot is not the same as, theoretically, calling someone a fascist for simply being in the DEA.
Marine isn't capitalized in the middle of a sentence when referring to an individual like soldier, or sailor.