You've missed an important part from my quote.I don’t know the divers in question, and have no first hand knowledge of this incident... I will only say that historically, we have seen that non cave diving instructors have fallen victim to what is a deceptively understated danger on several occasions. Unfortunately, We could come up with a long list of divers who “knew better” but still found themselves in way over their heads at the worst possible moment.
You've missed "or better, what I hope" because I really hope that an instructor doesn't behave like that...
But unfortunately, as you said, the world is not a perfect place.
...and also, he was italian, so for many of us rules are not really rules, but mostly guidelines.