From what Raistlin has explained, he was winning, and by mistake put Rubah's king in stalemate. It is considered a draw. Don't worry, I've made that dumb a mistake before too (3 queens vs a king).
I have included some links to help you better understand the un/fortunate outcome of the match (depending on what side you were on
http://en.wikipedia.org/wiki/Stalemate
http://www.chessvariants.com/d.chess/5.html
