Deliberate mistake: When Dale calls Hank from John Redcorn's trailer, the wooden clock behind Hank (in the Hill's kitchen) has no markings or hands to tell what time it is. This is a mistake as it is the exact same shape and object as it was before this episode and I doubt they replaced the clock with an completely exact object as before. A side note on the mistake is that it may be considered deliberate as the clock in previous episodes is shown frequently in the background and will generally change between shots.
Continuity mistake: As Hank is telling Bobby to give his speech at Thanksgiving everyone moves in around Bobby. If you look at Bill he comes in from the right even though he was on the standing to the left of Bobby in the previous shot.
Continuity mistake: At the start of the episode when Hank gives Bobby the turkey knife it is in a red padding. Just as he's about to carve the bread (for practice) the padding is now yellow and stays that color for the rest of the scene.
Continuity mistake: During the scene where Bobby is accusing Hank for the first time of taking Native American land you can see Bill is standing behind Bobby. In a close up shot of Bobby, Bill is now standing to his right. As Bobby starts walking Bill is behind him again.
Continuity mistake: Before John Redcorn gives Joseph the Horn & Feathers cap, he is driving and you can see there are white lane markings on the road to the left of the car. After Joseph leaves the markings on the road disappear for the rest of the scene.
Continuity mistake: In the scene where Bobby is refusing to partake in thanksgiving celebrations and Hank starts asking him whether he's nervous about the turkey carving. You can see Bobby's carving knife is pointed toward the wall with the blade (curved edge) pointed towards Bobby. Before Bobby picks it up to give back to Hank its facing the other way.
Answer: If you are talking about the "Thou shalt not do this, thou shalt not do that" song, I'm not sure if a song like that actually exists. Green Day, the guest voices on the episode, might have just been improvising to keep their appearance from being too obvious.