It may well have been genuine.  It probably got reported by someone that doubted it.  If the receipt was shown in the listing as the sellers other items do then that should have been enough, but in this case the sellers receipts come from different states and possibly countries.  One is a foreign language from what I can see.

If you look at the feedback that is a hell of a lot of designer bags for a private collection.  

Also, if you have a replica (fake) you can't  sell it on ebay even without naming the supposed brand.  If the item is badged with a name. then it can't be sold here and shouldn't be sold anywhere in Australia although markets and stalls get away with it for a while.