Originally Posted by Pogue Mahone

It's all to do with the referee's report. They can only add to a player's punishment if the ref makes an additional note in his report about something to be looked into after the game which he couldn't adjudicate on at the time (i.e. misbehaviour after already being sent from the field or play).

Either that or if the ref misses an incident altogether.

All a bit illogical and stupid but this is the FA we're talking about