If one of your Pokémon was Poisoned, and a few turns later it is KO'd by the Poison, does your opponent take a Prize card although the Poison KO'd the Pokémon, and not your opponents Pokémon?
Yes, he would still draw a Prize card. Whenever a Pokémon is Knocked Out, the other player gets Prize cards -- even if you Knock Out your own.
Source: WotC Chat (2000-02-10)