Kiba: He must have died resenting those who'd seized his castle.
Hinata: But he also lead us to where the scroll was hidden.
Naruto: You figure he finally decided to let go of his grudge?
Kiba: Seems that way. Or heck, could be he thought fifty years was long enough to keep that summoned animal in his service. Maybe he just wanted to let the poor old beast to return home.
Naruto: Think so? Then maybe he needed help releasing that creature from its imprisonment, freeing it.
Hinata: And now it's finally home.