Those pics are from Serenity LA (I was fortunate enough to go - Nathan crashed the gate).
It's a proto, and everyone who wanted to handle it was told that the real proto grips weren't yet finished and the ones on there were just so it had a reasonable grip with no bare metal.
Becuase the grips were just temps, they were pretty loose. Looks like that shot was taken after someone played with it. I wouldn't sweat it - the real grips are yet to be done.
(Mark Sheppard spent a good couple of minutes winging it around and clicking the trigger / hammer. Blame him. And Moomoo - you're right about the lighting. Holy crap, was that place dark. I think they had a couple of bare light bulbs on wires lighting up the the entire off-stage area.)