Drunkenness in aircraft
139.—(1) A person must not enter any aircraft when drunk, or be drunk in any aircraft.
Allowing the people to board in the first instance is against the ANO and as such I don't think Ryanair has a leg to stand on, Worse than this they have a legal duty to ensure the safety of the passengers and crew.. if this were the US there would be streams of court cases following this event. Of course its small beer ( forgive the pun) but again free publicity for Ryanair. the " caring airline"