Army Major? Do you mean Josh Duhamel? Because he and Tyrese were actually Air Force special forces, not Army. Most of the military personnel in the movies were Air Force, in fact.
Actually I got a notification the other day asking for military extras to come and be in the movie for a few days but I live in Cleveland (almost an 8 hour drive) and had a somewhat busy week scheduled. Apparently all that was required was arriving with ID in hand and in BDU/ACUs (standard work camo). They needed like 30 people for the parts and they wanted actual military personnel if possible. It was for 3 night of filming and apparently for a few good parts in the movie (good amount of on-screen time). Just stinks I had so much crap going on this week!