Nothing to do with the Daily Mail
I think you would find that an EU wide flight ban would be challenged in the ECHR on the grounds that it restricted the rights of free movement that all European citizens enjoy, an individual airline is of course free to chose who it decides to serve or not.
Lets just see if Mr Marshall quietly pays up or decided to ignore/fight Jet2 invoice for costs, if Jet2 have served him any alcohol on board then i suspect Jet2 would fail at court. They would also have to prove that the diversion was necessary, not a knee jerk reaction by the Captain to the CC complaining about some one supping their own alcohol, a court might find it contradictory that someone is allowed to drink alcohol on board, but only if it was bought on board.
I am not in anyway defending this idiot, but short of making flights a no alcohol flight its very difficult to get balance right for both the airline and passenger, but unless your flying on a Privilege aircraft, few would see flying in single class a privilege these days......