In the early days of red and yellow cards I once saw Norman Glover caution a player and then lifted up and showed his notebook instead of a yellow card. Everyone, including Norman, just laughed when it happened.
For goodness sake, what is the matter with the FA? Presumably by the severity of the sanction they believe Mr McNamara has brought the game into disrepute. Well, judging by some of the shenannigans that the FA has allowed on its watch, they have a very distorted view of what makes for disrespect.