I don't personally think it's the operator's screw up at all. Not even 1/10. It is entirely the diver's and his buddy's responsibility to make sure that the team is ready to hit the water. If the boat crew assists in setting up gear, that's a bonus (and may deserve a tip) not an obligation. The obligation rests squarely and completely on the shoulders of the diver--quite literally, too, since the tank is strapped to his back.
Here where I work, we often set gear up for our divers, or at least assist them. But we leave the air off after we test tank pressure for the duration of the boat ride out. Once we reach our dive site, it's up to the divers to turn their air on, release the bungies or whatever is holding the tank, and gear up. It's no more our responsibility if the diver forgets to turn on his air than it is if he forgets to defog his mask or strap on his dive computer, or grabs the wrong fins.
New divers often feel a little rushed. It's one effect of task loading. That's why it's so very important to go through the checks consciously--it slows things down and keeps your thinking organized so that oversights like forgetting to turn on air are prevented.
Here where I work, we often set gear up for our divers, or at least assist them. But we leave the air off after we test tank pressure for the duration of the boat ride out. Once we reach our dive site, it's up to the divers to turn their air on, release the bungies or whatever is holding the tank, and gear up. It's no more our responsibility if the diver forgets to turn on his air than it is if he forgets to defog his mask or strap on his dive computer, or grabs the wrong fins.
New divers often feel a little rushed. It's one effect of task loading. That's why it's so very important to go through the checks consciously--it slows things down and keeps your thinking organized so that oversights like forgetting to turn on air are prevented.