and no paying passengers inconvenienced
Surely the paying passengers got what they paid for, a business class seat. They just missed out on a free upgrade to a first class seat with business class catering probably, due to the aircraft change.
Badly handled all around by the look of it. When you add Thai national idiosyncrasies to the mix this was inevitable.
Don't shoot me but, why they deadheading crew didn't choose to go back to the hotel in Zurich if the seats are not what they are entitled to contractually?
Perhaps they actually wanted to go home to be with their family?