of course, the standard is the best in town, that's why 4 shops use that air fill, the tanks that were used, were owned by the guide, and all the equipment used was the guides. there has to be another underlying reason, the tanks from the shop were filled at the same time, as were the other shops and since the date, tanks have been filled, with no problems. there is a full log of filter exchange and cleaning of the lines available. which may lead to the air that was left in the tanks from the previous fill which wasn't the shop in question, (if bad air was the case) in which case, it wouldn't be detected as the air going in to the tank was clean. the reason i am jumping onto the newspaper sites is that the jury has been already decided and its the air fill. which is a very good way to ruin the reputation of a very good dive shop, that has done nothing wrong. in all cases, it is not determined what has happened, again, it is a very unfortunate event.