Continuity: When Wynn looks at Rains' file, the drawer her file is in is slightly open before he finds it. The shot cuts to Dodd reading the paper, then back to Wynn, and her drawer is shut.

Revealing: When the man is melting after being covered in acid in the beginning, you can see a wire pulling the "melted skin" off his arm, at the bottom of the frame briefly.

Visible crew/equipment: When Rains wakes up she stands up and shouts "Where is she? What have you done with her?" you can see the camera's shadow moving on her.

Revealing: When the blond woman gets slammed into the wall by the black man, watch the wall when she hits it. It vibrates badly showing that it was an actual set wall instead of the thick steel of the cube.

Visible crew/equipment: In the beginning when the man comes climbing down the ladder you can see a tape marker on the floor. When it cuts it's gone.