Originally Posted by
FlightlessParrot
Could have been someone having a loan of a new chum, but there are famous cultural incompatibilities. My favourite, relevant to the context, concerns the Australian colloquial expression for a minor greebie (and this is one I've heard people using IRL). Australian woman goes to London for working holiday, catches a bad cold, rings the office to call in sick and, in total innocence, says "I can't come to work today, I'm in bed with a wog." Also a once common Australian brand of adhesive tape which caused similar problems when approaching UK stationery departments: Durex.
My info on hand signs was NSW, '60s, where the middle finger was only known to people with an interest in Americana.
Edited to add: Quora thread
Thumbs up in Australia suggests that my memory of a long time ago is perhaps accurate, though maybe it was only used in such coarse places as the NSW country.
As Shaw said, perhaps here we have another two nations separated by a common language?