Derdiyok passed to Fernandes who was off side. But Fernandez didn't get the ball, it bounced back against a Spanish defender. When Fernandes did get the ball, he wasn't off-side anymore. It went too fast for any assistant and it all happened in 2 square metres of field. The scrimmage didn't make it any easier. I don't think we should blame in on the officials here.
By the way, that goal made everything a little more interesting.
Our friend Croref saw a computer animation of the goal and ha says it was definitely not off-side.
Damn those computer animations, they spoil all the fun!