At the start of the game with the second set of contestants, the "correct answer" flip over panels for the first set of contestants have still been left flipped over. Bernie Winters and Lynsey de Paul can be seen putting them back in place while looking out at someone off camera, presumably a crew member.
During the first "Supermatch Game", the sliding panel to the second answer is slightly drawn back when the first is revealed. When the camera cuts back to the Supermatch board, the panel has been slid back in place.
When Ruth Madoc is revealing her answer to the second question, one of the offscreen panellists (possibly Lorraine Chase) brushes past a desk microphone, causing a distortion sound.
Terry piles up a selection of food (given to him by Bernie Winters) on the question holder. When the stage revolves after the first game, some of the food falls on the floor. When the second set of contestants have been revealed, the food has been placed back on top of the question holder, much to Terry's amusement.