When Bernard is coming to serenade his summer girlfriend with an accordeon, dents can be seen on the accordeon from Bernard kicking it in a previous take.
At the end of the episode, when Manny is jumping on the car with "EAT ME" written across his front, the position of the word "EAT" shifts right noticeably between shots.
Manny goes to the oven for another copy of "Tempocalypse", but he doesn't need to. There's a whole shelf of them still on the sales display.
Manny uses the Fahrenheit scale despite being British.