Neither was a booking, I hate Arsenal almost as much as i hate liverpool, but I have to say that they were very harshly treated by the referee with those two yellows.
How wasn't the 2nd a booking? He went in studs up, way over the top of the ball and if that wasn't enough he also led with his arm and cracked Arbeloa on the chin. May not have been any intent but it was clearly a dangerous challenge.