While not having the air supply turned on is a possibility, I can attest (14 dives with them since December 2024) that the crew on the LadyGoDiver are very good at ensuring that everyone's air is turned on before jumping off the transom. While not as coordinated as a DM led group exercise as depicted several posts above, the DM (or DM's depending on how many divers are on the trip) check for the air being on when they grab the tank's valve stem to steady you before the jump and prior to releasing you.
But it also could be that the diver lost his regulator when he jumped in and could not locate it or his octopus. The very same thing happened to me (although on the boat and not the water) when I dove my BPW for the first time. I think the tank may ride differently and the usual motion of swinging my arm back to locate the hose was coming up empty. My buddy had to locate it and hand it to me. I quickly made a mental note to get a necklace to ensure that the regulator is not further than my chin, and relocated my octopus to the top part of my right shoulder, also very reachable.
Also, I looked up the conditions on Saturday morning and it was breezy, 14-17 knots, but it was from the West. The seas were running 3 feet and the forecast called for a shift to the south later in the day. So the conditions, in the morning, were dive-able especially for a boat the size of of the LadyGoDiver. However, the conditions deteriorated rather rapidly as the shift to the south happened faster than expected.
I have had dives on the LadyGoDiver being cancelled on the morning of the dive (I dive with them a lot - love the boat and the crew) when the conditions are 5-7 feet waves and higher. So I do not believe it is a scenario of them going out at any cost, I do believe that the conditions were dive-able in the morning. Indeed most dive operators went out that morning.
Having said all that, I am not certain, but is it the DM's responsibility to ensure that everyone air is on? Obviously this is a good practice and should be done, but the question is, is it their responsibility? In other words, is there a gross negligence (they know they have to and did not) claim if a DM does not check for air being on? I was always taught that the responsibility lay with the diver to check their gear - and of course all Liability Waivers specifically denote that everyone is responsible for checking their own gear.