When Barney is challenged to make a point to Ted and Marshall. He then says "Stay with me. It's gonna come to me" and raises his left hand as seen from the front. The camera then shows him from his back, and his right hand is raised. Then it shows him from the front and his left hand is raised.
When Ted and Mary are shown exiting the elevator the down arrow is lit up despite the earlier disclosure that Ted and Mary were going upstairs.
When we get a close-up at the TV while Sandy Rivers is reading the newspaper, we see an ashtray on the left side of the TV and some Tapes and DVD cases, but when Ted comes to pick up the "costumes", there are some canisters towards the left side of the screen (right from spectator's view) and a box (with the "costumes") appears right in front of the cases.