first of all, i'm not here to question the authenticity of this hermes bag, the hermes could made a mistake which had happened as others posted their experiences.
second, just want to say the super fakes are so good even 10 years ago, there was a limited edition bag in my hand was copied so well it would passed authentication by just photos or even a slightly careless check in person; and recently i have had some newly made super fakes (in hand inspection) were absolutely like the original ones, the only indications they were fakes were from the accessories they came with and one small detail i could tell they were super fakes. these super fakes were under $1,000 value bags they copied.
so i truly believe for the value of hermes birkin, yeah, they could make fakes so good even in person an expert couldn't tell, i would just buy it from the store pay the full price even if i had to wait for 2 years on the waiting list or buy it for half price from individual and never send it to the store for spa or whatever.