What's The Best Uno Hand?

I was playing Uno with Yu-Jin last night and he was really excited about one hand that I dealt him. He kept going on about how good his hand was. When the hand was finished he had lost and I'd picked up 20 points. What was so extraordinary about the hand he had been dealt? He'd been dealt three Draw Fours. How on earth can you lose after that?

Don't worry, I rubbed it in.