Don't forget the ludicrous sending off of Abidal. If that wasn't a huge advantage then I don't know what would be.
At the end of the day Robert, you can cry and cry about the "penalties" that weren't awarded. But you were 1-0 up and cruising against a below par Barcelona side playing with 10 men at home. You should have easily been able to see them off. And yet, Barca still dominated possession an Chelski still couldn't get their passing sorted out. You should be blaming Chelski for throwing it away.