Continuity mistake: When Leonard and Raj are getting ready in the bathroom, Raj picks up a tube of shampoo/conditioner off the bathroom bench with his left hand. However, in the next shot, Raj has nothing in his left hand and the tube is back on the bench, with no time for him to replace it between shots.
Revealing mistake: Near the end of the show, the big robot is chasing the other robot down the hallway. The camera starts to zoom in as the robots come by it. The big robot stops just before the camera zoom is past it, yet they keep running down the hallway like the robot is still going.
Continuity mistake: When Leslie and Sheldon are talking to Dr. Eric Gablehauser in his office, in one shot Eric throws a piece of paper onto the desk behind him (next to the computer.) Through the rest of the scene, this piece of paper keeps changing position. (00:09:00)
Continuity mistake: Right at the start of the episode, Leonard kisses Penny. When he starts kissing her his head is tilted to the right (opposite side to the wall with the camera). When they move to the camera image, his head is tilted to the left (on the side with the camera), and when they move back his head is back tilting to the right again. (00:00:30)