As I understand it, hydro testing is the responsibility of the "authorized recycling center" (the merchant) and not the place that actually refills the tanks for the merchants. The problem there is that (at least here in Texas) there are no merchants that have the equipment to test the bottles, they just have to be certified to be ABLE to test the bottles, and that is apparently good enough.
Again, who BBQs with propane anyways, besides Hank Hill? Real smoke beats liquid smoke any day.