Short or episode?
If you look at for A SquarePants Family Vacation at Itunes, you will see that "Sandy's Vacation in Ruins" comes as a bonus with it. If they plan to air that episode in future, they won't make that episode available for purchasing on iTunes first. Altough it has same opening as an episode, which made that episode put in the list in first place, because of reason above, it should be counted as a "A SquarePants Family Vacation short". On Wikipedia they have already done that. Do you agree?