With the Irishman coming in for a torrent of Twitter abuse from the public and making seemingly sexist remarks, without realising everyone would see them.
On the other hand, given Mr O'Leary's tendency towards outspokenness and his ability to court controversy, the whole episode could have been PR gold as the airline went viral.
The chief executive was supposed to field questions using the hashtag #GrillMOL on Monday, yet he didn't appear to understand how hashtags worked or what their function was.
One of the first questions, from a woman, drew the response: "Nice pic. Phwoaaarr! MOL"
After a host of complaints, he later added: "Just found out what hashtags are. Learning on da job! Always compliment ladies pics."
The Q&A session was always bound to be an interesting experience, given Mr O'Leary's reputation.
Among the questions fired at the airline boss was: "What type of people do you enjoy mistreating most?"
Mr O'Leary was also asked: "Is there any truth in the rumour that you plan to charge passengers for each inhalation they make after take-off?"
And Ryanair's policy of using 'secondary' airports was also drawn upon, with one witty poster claiming he tried to send a question on Twitter - but it ended up on Facebook ...
Mr O'Leary didn't seem too bothered by the abuse though, often replying with his own usual brand of humour.
One Ryanair employee joined the conversation by tweeting that his boss was currently on Twitter - only to get a reply from Mr O'Leary reading: "Get back to work, you slacker or you're fired."
Ryanair's official Twitter account did post on Tuesday about Mr O'Leary's social foray, saying he was now facing "another grilling" at a conference in London, complete with the hashtag #NoHashtagsThisTimeThankGod.