Cant tell from ur render. But if u RAM preview with no motion blur... But u render with motion blur it can cause flickering between layers that have either the exact or very close to the same value in zdepth.
Mattew's suggestion is the first thing I would check, just move the flickering layers like the collar in front of the other layers by a pixel or two. The other thing it could be is if you have any layer styles applied to 3D layers it can cause weird flickering problems in the render. It's been an issue since CS3 and still hasn't been fixed.