I read on Chinese social media that because the buyer was hang out with friend who had the same bag, they compared and found out buyer's looks different. That's the reason the buyer told to court. Another argument was buyer tried the bag in the boutique, took pictures. When she tried it on, the bag was real. Then SA took the bag to the back and pack it for buyer to take home so buyer didn't really see the whole process.
This is heavily discussed on Chinese social media especially because not long ago, one of the
Gucci boutique (in China) was just caught had one employee being swapping fake to real bags for a period of time. (I forgot it was a month or a week)