So yeah, when Littlefoot is defending to his grandpa in III why he and his friends were in the mysterious beyond.
I thought, even as a kid, that this was felt like a really unnecessary "correction". Hyp, and---to a lesser degree---his friends were bullies and, at the moment, hadn't even reformed.
Now thinking about it again, perhaps Littlefoot didn't want to provoke Hyp into bothering him and his friends anymore, and that was why he was so polite.
Also, did it ever come across as strange that Littlefoot never, well, discussed the bullying situation with his grandparents? I mean, Hyp pretty much threatened to kill him, Cera, Petrie and Ducky. That's not exactly something I would not tell my parents about!