After reading the recent speculations I feel like I need to say a few words.
To date, using the same set of photos, multiple authenticators have provided opinions and each has come to the same conclusion about the bag's authenticity. It is unfair and to me highly inappropriate to depict the picture that the authenticator I worked with prior to purchasing is in "blatant" denial of any potential error. Her opinion is verified by equally reputable peers in the field.
The seller is also beyond cooperative and supportive, and stands by her "life long money back authenticity guarantee". We are just awaiting to receive the Letter of Expertise and Affidavit before processing the refund, which I think is a very fair call by the seller. Meanwhile the seller was able to get in touch with the previous owner who happens to have kept one email exchanged with FSH about the exact bag. Now with a reference number, it opens up the possibility of querying for more info by someone within Paris HQ. The previous owner seems to be in a much more favourable position to directly get in touch with Paris HQ. Hopefully she can make a difference there.
Hermes being the creator, without being close to any VIP status, I feel my voice is falling on deaf ears.
I am so, so sorry what you are going through.
I think the number of conspiracy theories laid out here is laughable.
OP, I'm sorry people have to complicate things.
You bought what is almost certainly an authentic bag and had it authenticated by the top authenticator in probably the world.
Authentication by photos is different than by hand but there are tells.
The fact that your bag went through three levels of checking at HQ means they themselves were unsure. Whatever it is they are seeing or not seeing is probably an anomaly in your authentic bag.
I am not sure I believe there are many, if any, people left at Hermès whom I'd trust absolutely in authenticating a bag more than ten years old. I certainly don't trust H unequivocally in these matters.
The odds of anyone special ordering a sellier Mou from a super-fake manufacturer with that date stamp, etc. - I won't go into detail but the evolution of the superfakes makes it very, very unlikely.
You have an owner of the bag, a trusted reseller, an authenticator/world-class collector, and a new owner of the bag, all but one of whom have held the bag in their hands and all of whom feel it is authentic.
All the posts from people who have clearly never worked with bababebi - better to talk about what you have experienced yourselves. She is respected worldwide as an expert. I trust her and believe that she would absolutely come forward if she believed she had made a mistake.
Of course it is all possible - a superfake Mou that slipped through this many experts. It's just very, very unlikely given all the above.
I'm hopeful the previous owner of the bag will be able to find you a paper trail that will support you. We are all (ok, most of us apparently!) still pulling for you and your Kelly.