a few things give it away
the Australia classifications are stickers, not just part of the boxart
the game ID code will have an "A" not an "E" ie. BLAS-50342 instead of BLES-00933
printed in Singapore
the text "for more information visit
http://asia.playstation.com"
a few words have Chinese translations added
also in the small text on rear there is nothing saying "licensed for use only in"
just make sure to check out the rear cover, the front covers are pretty much identical (besides the sticker)
edit: more users starting to find out about this issue -->
http://community.eu.playstation.com/t5/Technical-Help/Bought-Rockstar-pass-no-DLC-in-game/m-p/13294035/highlight/false#M87324