I was wondering this too. My stinky bags were all Q and R and in Togo. The leather to me felt dryer even though the bags were new. I am not sure how the bag would have aged because I returned them for the exchange months ago. The smell was overwhelming and there was no way that I could live with it. As far as testing, my store told me that they really can't do anything but sniff it locally, but in Paris there is much more sophisticated testing going on both of the bags that are coming in and those being shipped out to stores around the world.
As a matter fact, I literally saw the sales person sniff my bag and originally told me that everything was fine. It was a month later that I took it back because the smell had gotten so bad and requested that she send it to Paris to confirm that it was a stinky bag.
I think locally, sniffing is the best they've got. I'm glad that I was persistent. That was in the spring, before all this became more common knowledge. By my second bag this summer, the SA immediately took it in and gave me a receipt without trying to smell it or anything.
By the way, I had one of my bags in my hot trunk for days and it never triggered the smell. It was only a week or so later when I took it out in the sunshine on a moderately warm day that the smell first became apparent. After that it was worse and worse by the day. I strongly believe that if you're going to test your bag, you need to take it outside.