I believe that the Third Match Official TMO, is watching the 'action' footage, where inevitably cameras follow the ball / play that is about to occur. Post match citings in rugby occur, when all the un-televised footage is watched. I wouldn't say that it happens quite a lot as
@nejohn suggests. There is a rugby mantra 'Body in the furnace, head in the freezer'.
As for respecting the referee, trying to influence the referee is one thing, arguing, shouting and some of nose to nose confrontations by football players against the referee, just wouldn't be tolerated in rugby. If a player verbalized disagreement with the ref, then the player's team was marched back tem yards. I have even know a referee march a team back twice in sucession, behind their own try line, with the comment 'keep going and you will be behind your own deadball line'. Usually for the team being marched 10 yards back is enough for the rest of the team to tell an arguing player to 'belt up !'.
I have coached junior rugby from the age of 8 upwards, and respect for the referee starts at junior level, the message being,you may not agree with the referee, but he is the law.With oider teams I have coached I used to say play the referee as you would the ball, you can mention that the opposition are doing x against the law of the game, but don't disagree with the ref, as he isn't going to change his decision. This is something that on the whole the parents of junior players pick up, when they are on the sidelines. I can't say I have witnessed much in the way of parental dissent directly aimed at the ref or if so not loud enough for him or the players to hear.
That's not to say that at senior level things are the same. Rugby is a full on contact game and yes it's inevitable that foul play will occur, the ref / linesman should deal with any 'techical' against the law foul play, the odd sneaky punch in a maul or ruck, was usually rewarded with the same. Given the opportunities there are in the game, it goes on a lot less than non-players would expect, Rugby laws and acceptance by referees to 'handbags' as it was called, has disappeared in the modern game. In the Good (bad) old days of rough rugby, can recall a game being called off 20 minutes from the start, due to the number of punchups there were and the ref simply having had enough.
I can't comment on football as I don't watch it, but the yellow card and sin bin does work, as does the TMO and the assistant referees (they will always be linesman to me) each with the ability to step in and advise the ref of foul play and thus reduce it.