Actually Crowler should have won when his AGG attacked Winged Kuriboh. Why? Because Winged Kuriboh's effect won't activate until it is sent to the graveyard, so AGG's piercing damage should have occurred first. But that's just how the anime was back then, I think it is following the rules pretty well now.
It's not an error, it works that way consistently throughout the series. It just works differently in the anime to RL. (Presumably it just also has an effect similar to, say, Monk Fighter's, though its text in the Japanese anime doesn't mention it. Which isn't rare even for explicitly obvious parts of effects anyway.)
What do you mean winged kuriboh had no place in jaden's deck? I mean he has a deck where e-heros fusion, neos, neo-spacian, and mothafuking YUBEL all mashed up in 1 deck. Of course winged kuriboh is a perfect card choice for his deck.
It's probably the right time to mend your ways and speak like a saint in this site from now on. You Anons have caused so much irreparable damage to this site's reputation.