I don't really agree that words can be more painful than fists. Physical attacks can do a lot more, cause more pain, even kill. Words can be hurtful, but they can't be as painful as a physical attack, in my opinion.
There is something about that fight scene that I just noticed. I wonder if Littlefoot had a bit of an anger control issue. No, I'm not referring to when Cera gave the insult; I'm talking about just before it. When Cera tried to leave and Littlefoot tried to stop her, already he seems pretty ticked off, even though Cera hadn't given any kind of insult at this point.
I wonder how far Littlefoot would have gone had Cera not given the insult. Would he still have attacked her simply out of frustration? Would he have let her walk off? For me, I'm not really sure how things would have gone if Cera hadn't given the insult.