I really would like to know, as I don't believe the country is best served by basing such an important decision as to who to take into the military on knee jerk reactions to recent tragic events or anecdotal accounts, but rather properly conducted research designed to avoid common pitfalls such as shown in my "lunacy" example above.
As much as I respect your empathy for Johnny and obvious sense of 'fairness' there is something you seem to be forgetting. The decision as to who the navy recruit is all about who the navy need to fulfil their role versus who they can get, currently there isn't a problem getting young people in the door, as long as that situation exists they won't take any risks that they don't have to it's as simple as that, the logic is infallible, why should they follow an illogical route and add potential risk to recruitment.
I know it seems that the focus of this sort of decision is on the individual, it is after all they who may have their lifelong dreams dashed in a second, in reality the focus is the interest of the service and ultimately the country. The reality is that this is a decision that is unlikely to be changed unless the number of available applicants takes a dramatic drop and the navy 'need' to look further afield to meet their recruitment targets.
There are plenty of other equally challenging, adventurous and rewarding careers out there, rather than waste a big chunk of energy dwelling on something that has passed it's best to focus the mind on something of worth.