-When Kurt encourages Finn to sing his ballad to his baby, he sits down at the piano to play. He's wearing brown leggings, but when they scan to his hands playing the song, blue jeans are visible for an extended time.
-When Suzy Pepper eats the worlds hottest pepper (after Will lets her know they'll never be a couple), a strand of hair can be seen in her mouth. Then the strand disappears on side shots, but reappears in her mouth when she finally chomps on the pepper that burns out her esophagus.
-When Kurt answers his cellphone when he's ironing he leaves the iron down but when the shot changes it's up (so as not to burn the clothes).