Do we know for certain that the costume has been changed? OK the switch from blue to red boots is certainly a good thing, but seeing as this is an action scene, and half the shots are of a stunt woman, it's possible that the non shiny pants are to give better movement, and for long shots only.
OK, maybe I'm alone in this but I liked the shiny pants.
You are not alone...

And yes, the stunt woman has quite the nice shape to her as well. I'd also like to point out that Liz Hurley (at 45!) is looking smoking hot, too. I think I'm going to have to check this show out.