He lived with one of them on a lifeboat for quite a while. He hasn't been around humans since his parents died. Then his mind went into survival mode. And sometimes survival mode means animalistic behavior. “I will also confess that, driven by extreme need and the madness to which it drove me, I ate some of its flesh. I mean little pieces, little strips which I meant for the hook of the gaff which, dried in the sun, looked like ordinary animal flesh. They slipped into my mouth almost unnoticed. You must understand, my suffering was incessant and he was already dead” (chapter 91). He just ate the French cape with Richard Parker. Sure, he was dead, but this proves even more that Pi had adopted animalistic behavior to survive. Pi wouldn't have done it alone. In fact, the French leader would not have died if Richard Parker had not been there. Pi wouldn't have gotten this far without him. He would have died in the middle of the ocean if Richard Parker hadn't been there mentally forcing Pi to fight