I'm going to cut the guy a little Slack. It seems to me that the whole purpose of this story is because he and his team are raising money for charity by doing the mountain climb.
He used the same expressions a couple of times. For example, he refers to the other three divers with him that day as other dive professionals. That doesn't make them all instructors, probably divemasters, or one other instructor and two divemasters.
He used a phrase including "disparities", when telling about the surprise of finding themselves out of air but he also emphasizes all of the signaling and slate writing etc., to make the ascent plan from OOA at depth. To me, he's using a euphemism to replace longer winded explanation of seeking the missing tanks, etc.
As unlikely as his story, has seemed, it is far more unlikely that all 4 noticed they were out of air and so did a bunch of signaling and slate writing to decide how to ascend. My wag is that the note sharing occurred when they couldn't find the tanks. In other words, they drafted plan B on the fly but whilst they still had some remaining air.