I've noticed the same issue with the Carrier Special Rig Black (V_PlateCarrierSpec_blk). On the Virtual Arsenal and on Stratis - haven't tested Altis.
Load a mission with a soldier wearing the vest say 20m away, approach him, and watch the texture flip between black and green.
It also occurs with the green and black versions of the vest when retextured, flipping between the new texture and the green texture.
I have not noticed the issue in any way with the GL versions of the vest (V_PlateCarrierGL_blk).