This story was all over the media a year ago (July 6th to be precise).
It was nothing more than an opportunistic publicity stunt. There is no way such 'seats' would ever be cretified for crash-worthiness, aircraft capacities are strictly regulated according to the number of exits - it can not happen and O'Leary knows this perfectly well - but hey, why turn down the opportunity to get Ryanair's name in the press.