docmartin:
if you seriously believe it constitutes negligence on a customer's part not to check if a professional did his/her job right we have truly come to a very sad state of affairs and you have bought into it by blaming the customer. I have a hard time believing that a court or a jury of your peers would be this generous with the dive shop had they to contemplate a diver's death or serious injury under the circumstances described.
the average diver has absolutely no training that would enable him to ascertain if the service has been carried out correctly. furthermore, hooking a reg up to a tank at the LDS does not tell you much no to mention that more than a few dive shops do not exactly encourage this and act rather annoyed.
therefore, while it may be wise to double check if you know what you ought to be looking for it seems a bit far fetched to call the customer negligent if he places his trust in a professional (as we all do numerous times every day).
Blaming it on the customer? No. Negligent on the customers part
ALSO. Yes. Do you check your taxes, car repairs, dental work, doctors diagnosis or anthing like that? These items are ususally handled by professionals in their fields.
I'll give the average diver that you are talking about some indicators to look for when they pick up their reg that has just been serviced.
1. Attach it to a scuba tank and pressurize it.
2. If it flies apart, it's probably bad. Free flowing, probably bad.
3. Leaking around the hoses and first stage or ruptured hoses. Bad again.
4. Can't breath from the second stage. You might have a problem.
5. The LDS refuses to let you have a tank to check it with. You'll probably have a problem soon, and they have a real problem now and it's going to grow if I don't get a cylinder PDQ.
These are just some indicators, not an a complete list of possibilities.
It's just my opinion, but if you're smart enough to own your own gear, you're probably smart enough to know if it is breathing right or not. At the place it is serviced, before you leave with it.