Continuity mistake: In the close-up of putting the lids on the bottles, Mat's hands have 5 fingers (briefly done by a real person instead of the puppets). However, throughout the series, the duo is consistently 4-fingered - and that includes other close-ups that were also created with real hands briefly replacing the animation.
Continuity mistake: When Mat knocks out the door, which falls on Pat and squeezes him, he uses a hand pump to inflate him. After Pat comes to life, the hand pump disappears.