The Forest player wasn't already on a yellow (and didn't get one either), but that is academic as there was a clear stamp down with force on Pedro's back followed up by a kick when he was laid on the floor. Either should be red card offences, especially the first.
For the incident last night...
A Chelsea player was booked for kicking the ball away against us last weekend. Comes under the same offence Billy was booked for, delaying the restart.