Interesting story and i have had 1 major insta-buddy nightmare before, not going to thread jack and tell the story but i feel your pain, especially since he jeopardized the safety of your family. The only thing that i would have never done is ask him if he had a snorkel and suggest he borrow one (pre-dive), it is not my business to question his gear choices. Not questioning your logic at all just saying what i would not do. Glad it worked out for you and your son. Safe diving.