Indonesia ain't that far from Australia - could be either or - I've heard of Indonesian Yabbies but never having been there, I can't verify! But the health of the craw is more important than it's origin, right? - and I'm sure with all of the species varieties of Cherax there's bound to be hybrids and mutations galore...
That being said - Yabbies don't act the same as Northern Hemisphere crawfish... from my experiences they are better cleaners, less destructive to the tank and not as successful in killing tankmates. They are slower and North Hemisphere craws pinch harder too! But Yabbies are more territorial than craws. Yabbies don't like other crustaceans. Craws will fight, Yabbies kill. I found out the hard way by losing a beauty of an electric blue craw when I put the two in a 90 gallon tank thinking they had enough space to share.
Also my Yabby doesn't come to the surface or climb out of the tank like so many craws have.