If I'm honest that shouldn't have been a penalty

after seeing it again that was a harsh penalty given against Marshall no way should that had been given the Rotherham forward should have been given a yellow for pulling marshall

After looking at the highlights again, I can see why the red card was given. However, the original foul was by a Derbyshire, and should have been given as a Cardiff free kick instead of a Rotherham penalty

My opinion,
Cardiff Freekick and Marshall Red card.
Derbyshire committed the initial foul.