The crew departed Fes with the optimism or reaching Beauvais before curfew. But alas it did not happen.
There are a number of countries beyond the European borders, even with a delays, will not allow passengers to deplane, and return through immigration back into their country. Same holds true for those passengers who have gone through airport security. So is the alternative to have passengers sit on the Jet without free food or water in Fes until 03:00? Not a prayer.
Yes… Beauvais, a neighborhood friendly airport after hours, which is some one hour from Paris, closes its doors rather early. Sometimes Beauvais can be coaxed into staying open a bit after their normal closing times. However this was not the case. Perhaps with direct routing and help from Paris Control, perhaps the flight could have reached Beauvais before curfew. But alas... the controllers that control the airspace around CDG are not the most cooperative nor sympathetic.
With that being said, Ryanair made necessary arrangements to have passengers bused to Beauvais. Passengers expect the skipper divert to Orly or CDG. Like in the US, one does not show up unannounced without ground handling, legal issues, as well as customs and immigration arranged… especially in France.
Now as for the situation in Liege... if maintenance is present at all times while the APU is running, and cabin crew are on board the aircraft, then the front end crew is not required to be on board. If there is a GPU then Mx, does not need to be nearby nor Pilots need to be onboard.
Now with the exception of the alleged abandonment of the aircraft, the pilots, did what they trained to do… divert to their alternate airport, which was Liege. The crew will be dealt with accordingly if they did abandon their aircraft and left it unsecured, in the dark, with no power on the jet or emergency exit lights illuminated for that matter.
I'm sure there's more to the story than what's being reported.