Well, she did take responsibility for the decision to dive. I would think the problem would be the bait & switch issue.
You booked the day based on 3 shallow dives as advertised on the website. The night before you get a call and it's changed. You only have the one day to dive, so you go along with it. I acknowlege that the operator was trying to get good viz for their customers by changing the plan. I acknowledge that they gave the customers the choice. I wish the operator had not mentioned that the 3 shallow dive profile was not profitable for their business, though. That is sort of what reeks of bait and switch, to me.
Yes, they could have decided not to go. But, as divers, if you have your heart set on diving, it is difficult to cancel at the last minute, without a plan B.
She said she learned from this experience. I think it was a good lesson to pass along.