When Nigel goes to Louis to talk to him about Louis being the new quartermaster, Nigel comes in with two boxes of pens and bars. In his hand the pink box is on top of the black box, then, when he sets it down on Louis' table, they change to black on top of pink, then the next shot they change back to pink on top of black.
When Donna approaches Mike to do some archival filing, the order of the files changes from shot to shot, first the blue files being on the outside, then swapped with the brown files outside.