He slowed down and positioned himself to take a rub of skrtels legs. Skrtel hardly touched him. No way was it a pen, really bad call.
"He slowed down and positioned himself to take a rub of skrtels legs" = he played for it, but it does not = not a penalty.
Just because he played for it 1. does not make it a dive and 2. does not make it not a penalty. It is harsh yes cause skrtel didn't look like he knew what he was doing. But it was a foul, it was in the box, it is a penalty.
As for Agger's Red. Any appeal will get laughed out and possibly get another game ban added on for a frivolous appeal. He pushed him. That means a foul a penalty and if he was last man and it was a clear goal scoring opportunity (which is what happened) then it is a red. There can be no argument.