It looked like Moyes thinking he was making an attacking substitution with Valencia running at tiring Sunderland players. You could almost hear him going "Happy now, RedCafe?!"
You'd have to ask him personally if he realized that doing so would let Sunderland push up with impunity into our already questionable midfield since the threat of a moment of bushido brilliance was keeping four Sunderland midfielders/defenders around Kagawa at any given time (AKA in their own half instead of leaving Carrick and Fletcher in their wake.)
Just the worst substitution in his time as manager. The only thing I can think is that Kagawa was tiring. But the effect was we had no one who could keep possession of the ball.
