I have different opinion as the seam is a mistake and not a defect from what I can see..
Although all the hardwares looks fine, I won't tolerate any single mistake..
Defect is different thing from mistake.
The authentic bag can have some defects such as bad stitching in some parts, scratch, crooked logo etc but I don't think a mistake can be found in authentic bag..And the wrong seam in the middle of the bag is considered as a mistake in my opinion..
Instead of small selma, I know there are 3 sizes of selma messengers which are mini, medium, and large..
I know that the bag in ebay link given isn't medium satchel but medium messenger by looking at the size of the bag posted by the seller..
Medium messenger is different and it's smaller than medium satchel.
But of course it's up to the buyer if they want to go to the professional authenticator and pay fee..
I do have same opinion as you.
