It is generally expected (and perhaps common courtesy) that people do not use their items out in public. At least,...that is my expectation. (Feel free to disagree. This is solely my own opinion and I do not mean to offend people)
I've always brought home items, and looked at it within the confines of my bedroom, but I've never brought items out in public to say...lunch...and pondered whether it was worth keeping.
A hair or two...that is something that you cannot control. It doesn't mean that the item was used. As mentioned, the hair could've come from anywhere...even from the Hermes artisan. (Cookie crumbs...that is not cool)
On the flip side of the coin, if you hold such a high standard for Hermes,...what about the jeans that you try on at say...the Gap or Macy's or
Nordstrom? Some items that have been returned, have a return sticker on back of the tags (Macy's and
Nordstrom does this), but there is no guarantee that the item wasn't at least tried on. And that is ASSUMING that someone was wearing "clean" undergarments before trying something on. Some people quite simply do not wear underwear. (I went to the Barney's Warehouse sale last week. A very charming individual was trying on a pair of paints. His underwear was...not so white, and had an extra hole or two not were not part of the original design! Ewwwww....)
At Hermes, when I purchased a scarf,...the SAs even tried on a scarf briefly to show how the item may look while being worn on a person. (I was trying on a scarf as well).
Not only that, but we've all tried on clothes in the fitting room...and you've seen how people treat clothes they've tried on (clothes dumped haphazardly on the floor, etc.).
Just one of those things in life.