Continuity mistake: When Theo and his parents are talking in the kitchen, there is a box on the table. The cover is on and Theo is standing in front of the table, the next shot he is standing next to the table leaning on a box and the cover is off.
Continuity mistake: When Theo walks into the kitchen, there are two half gallons of chocolate milk on the stove. When he sees the milk and picks it up there is only one. Theo places it on the table, later the second one reappears on the stove, before he leaves Clair gives him the one that is sitting on the stove, and the one on the table disappears.
Chosen answer: That is the song "Open the Door Richard."