Muzzle flashes? *some spoilers*

Not sure about the muzzle flashes but I started thinking about this while watching the film last night. The shot from the trailer with Weyland standing next to the guys shooting at Fifield and the Elder Engineer does lead me to believe there's a totally different cut of the film and Scott has a history to back it up. That history is called the Kingdom of Heaven Director's Cut. Not sure how versed some of you are in the 2 versions of KoH but there are huge differences. As in they HAD TO SHOOT THE FILM 2 WAYS. In KoH the Queen Sybilla character has no son yet in the KoH DC she does. This is more than a mere insignificant character that could just be cut out or left in without being noticed. They actually shot scenes with the son and shot them without the son. The son actually changed the story depending on if he was there or not. There's a lot more to it and a lot more to the DC than just that but it's a bit hard to explain. Basically, with the evidence of how Scott demanded to shoot 2 versions of KoH even though the studio thought the son's story "went off on a tangent" and pretty much made Scott take it out of the film(this is Fox too btw) coupled with the shots of Weyland being on the Prometheus BEFORE his reveal in the theatrical cut and the presence of the Elder Engineer leads me to believe that there's a lot more to the "extended cut" than Fox and Scott are letting on.

perhaps just different types of ammunition?

It did appear that a blue muzzle flash hit Fifield The Mutated One as he/it was about to kill that one crewman who spat blood into his helmet. It looked like it was supposed to kill, but it may have been just a stun round in the end.

Cryo bullets as in Sound of Thunder?

I'm still wondering what happened to the long-armed Fifield from the trailers.