In the ending scene, when everyone is finding out that the black guys were the Wilson sisters, there's is some bad mistakes in their eyes.

The first is when Tyrell is shot, and one of the 'white chicks' pulls off his mask. You can clearly see him/her wearing bright blue contacts, but when he pulls of his mask and you see his face, he's has his regular brown eyes.

The second one is the second white chick, with the same story. Blue eyes, but when his mask is pulled off and everyone gasps that she was a he, his eyes are brown again.