The colors of the boxes of cookies shot out of the gun at the mall are different than the boxes the customers catch; purple in the gun is green when caught, green in the gun is purple when caught.
To make money for their troop, the Bumblebees say they're selling muffins at the hockey game but they clearly have signs that say "cupcakes" on them.
When the hockey coach gives his speech during the Finals, before Alex interrupts him his mouth doesn't match what is heard.