I understand the philosophy behind wanting the shop to have some responsibility and it being too easy to waive away all our rights. Here in Canada, negligence cannot be waived, no matter what a dive shop tries to put into it's waivers. I fully agree that our right to sue for negligence should not be able to be waived away by us or for our children and that the U.S. should consider altering that too-easy ability. I think Ken's point, however, is that negligence is not really a factor here.
It seems to me that none of the arguments made by the plaintiff resulted in the cause of death. For example:
Negligence on the part of the shop: No, because the tank was empty at about 80 feet although it showed about 150 psi. Anyone who was certified is taught to arrive at the SURFACE with at least 500 psi (most of us reserve a lot more). If he was at 80 feet with even the 150 psi that he thought he had, he would not have made it to the surface with a prescribed rate of ascent even then or be able to do an adequate safety stop with that low amount of gas that he thought he had.
Many of us are taught that the last few hundred psi of an analog gauge is not accurate and we may not have as much gas as we think we have.
Basic certification teaches us to do a pre-dive check of all of our gear. If a gauge that is not connected or is connected but the valve is off and the regs are purged and the gauge is reading 150 psi, we know the gauge is off by 150 psi. This should have been caught when picking up the gear or at the latest when setting up at the dive site. One can choose to let the shop know, exchange the reg or choose to dive with it knowing that it is reading 150 psi high. Our training teaches us to check all of our gear and not dive with gear that we find to be faulty.
Basic certification also teaches us to check our gauges often and understand basic gas management. If he was checking his gauges often, he would have known his PSI and signalled Low on Air a long time before running out, but that apparently did not happen. Apparently he did not know his gas situation and did not begin ascending until he actually ran out of air, and this is contrary to our teaching.
Confusing wording on the "Title" of the waiver, indicating that it may apply to multiple days or boat dives: No, because negligence is not a factor here, so it is moot. The deceased signed the rental agreement and no one necessarily knows if the deceased realized that the waiver on the same page was intended to apply to him - not even his son. As divers, it is reasonable to believe that it is customary to sign a waiver before renting gear (or diving from a boat, partaking in a class, etc.) The intent of the rental agreement/waiver is common knowledge to any diver, especially an experienced one.
Too much weight: No, because we all learn in basic certification to do a pre-dive weighting check. If he was grossly overweighted, he would not have been able to make a controlled ascent all the way to the surface, and it was reported that he did make a controlled ascent to the surface.
It is routine for shops to give divers more weight than they think they need so the diver can make that decision as to how much weight they need, as they are trained to do in basic certification. It is also routine to give extra weights so that the diver can configure and balance the weights the way that is comfortable for them. One diver may want more 2 pounders while another may want more 8 pounders, and shops tend to give a variety unless they are told specifically what a diver wants. Our training requires us to do a pre-dive weighting check and use the amount that we determine allows us to achieve neutral buoyancy. It is customary for people, especially on a shore dive, to leave weights nearby and add or subtract as necessary before descending to depth. It is also recommended to have a bubble watcher to assist and watch.
We are also taught in basic certification that we can refuse or end a dive at any time for any reason and without disclosing a reason. We are taught that being uncomfortable while diving is not acceptable and a very good reason to thumb a dive. Diving while being grossly overweighted is extremely uncomfortable and a lot of work and the dive should be thumbed if the weighting could not be corrected. If the deceased was overweighted but not grossly so, the diver could choose to dive with the encumberance, as he apparently did or follow his training and either correct the weighting or thumb the dive.
Running out of air causing death: No, because the deceased and his son were able to make a controlled ascent using the son's air. The deceased did not make an uncontrolled or buoyant ascent or fast ascent, therefore the lack of air in his own tank did not cause his death or possible embolism.
Basic training teaches us that using your buddy's alternate air source is the preferred method to deal with a low on air or out of air emergency. The deceased chose instead to buddy breathe with his son, which is not a preferred method and is no longer taught by some agencies due to it's inherent danger. The son had an octo and it was not used for some unexplicable reason. If the octo had been used, it would have made for a much more comfortable ascent and would have avoided the coordination, cooperation and the constant swapping of regs required in buddy breathing while managing the ascent effectively.
It seems to me that while the argument against waiving negligence and other equipment issues are good ones, they don't seem to apply to this case. IMHO, this tragedy could have been avoided if basic training was followed from the start of the dive plan, and could have been mitigated along the way by the choices that were made by the deceased and his son at each juncture.