Where have you been living of course QF have every right to take action against crew when they are in a slip port
That's a load of tripe Galley Hag, unless you subscribe to the Big Brother priciple. Using that same line of "reasoning", QF would also have jurisdiction over crews living in SYD, because that's their base.
If it happened in The Truck, outside duty times, then it's got nothing to do with the Company, except that as a result some crew member(s) were unfit for duty.
If there's going to be any follow up by QF, it will need to be through the Japanese Police in Narita, and boy oh boy aren't the Japanese Press going to just love that.
As someone else said, what one does in the privacy of his own bedroom is his/her business, and NO-ONE else's.
But when some people start openly flaunting it and making a public show, it then becomes EVERYONE's business.