Harlequins prop Marler escaped with a reprimand after insulting Scarlets front-rower Lee in England’s 25-21 victory over Wales at Twickenham on 12 March.
England coach Eddie Jones scolded Marler before the Six Nations committee accepted his private and public apology to Lee as sufficient, opting not to impose any punishments.
World Rugby has since launched an investigation into the process behind clearing Marler, and could yet enforce sanctions on the 25-year-old, but Ritchie has backed the Six Nations’ disciplinary rulings.
“Let’s take some perspective and let’s not deflect from what we did in terms of the Grand Slam,” said Rugby Football Union (RFU) chief executive Ritchie.
“As far as Joe’s concerned, pretty clearly what he said was entirely inappropriate, he recognised that, he apologised very quickly and has apologised publicly since then.
“It’s pretty clear that nobody made a complaint about it, and I think Samson Lee’s reaction to it has been evident and he accepted the apology.
“Eddie and I spoke about it and when Eddie talks to someone that person is left in no doubt as to the appropriate nature of his behaviour, and that it should not be repeated.
“There was no citing officer complaint, there was no referee complaint, and the Six Nations looked at the matter fully as well, and came to a conclusion.
“So as far as I’m concerned that should be the end of the matter.”
The Quins front-rower apologised to Lee at half-time in the Wales match a week earlier, and is said to have quickly realised his insult was unacceptable.
Marler is not yet in the clear, however, with global governing body World Rugby expected to announce in the coming days whether it will take further action.