Taking your statement at face value, it only “proved” one thing: that on that particular occasion, with those particular people, that it was possible. Nothing more.
It is very unwise to use an example like that and then to extrapolate to calling it “viable.” Viable by whose definition? Define viable.
Confusing the lack of an obvious failure for success is both commonplace and dangerous. Unfortunately, mariners, professional and not, do it all the time. As do landlubbers in every walk of life. It’s that troublesome human-factor that clouds our eyes and trips us up. Which is what eventually brought about the existence of the dreaded formal risk-assessments that mariners have to use before even cleaning a toilet these days.
Flawless execution of a 100% successful at-sea rescue evolution completed via a well-planned procedure (with suitably trained, experienced & equipped personnel), adapted as needed on-the-fly and in real-time (because seldom does everything work out exactly as planned) is something that not even professional search & rescue personnel are capable of honestly guaranteeing, let alone delivering. It really helps to have good luck at the right moments, too. And luck (fleeting, unreliable & temperamental as it can be) tends to favor the well-prepared more than the less-prepared or un-prepared, but there are no guarantees of it. Ever.
Merchant seafarers are not professional search & rescue personnel. Not even close to it. Merchant ships are not purpose-built rescue vessels. They’re designed for various types of sea-borne commerce, and everything else is considered a cost to be avoided if possible. To the extent that vessel owners have been forced over the decades (and only after much needless loss of life) to better equip their boats and ships for emergencies, it is geared heavily towards construction standards, fire fighting and abandoning ship. Rescuing personnel from the water is typically, and sadly, down at the bottom of the list. The various marine regulatory agencies have mostly gone along with this, too. Passenger vessels are somewhat of an exception, but still have big shortcomings regarding what they’re capable of MOB recovery-wise.
So it really depends on the specifics of a ship’s hull-form, lifeboat location, davit system, etc., crew capabilities, and all the many other variables of weather and sea state but, in general, launching lifeboats at sea is, at best, moderately dangerous. Recovering them, if it’s even possible, would be very to extremely dangerous. Impossible? No. Too risky to try? Yes, in most cases.
Merchant seafarers are neither trained nor obligated (morally or legally) to try to do “everything possible” to save someone. Professional search & rescue personnel, while trained for it and much better equipped, are likewise under no obligation to do “everything possible.” You do what you think you can, taking the risks into account as best you can, and hope it all works out okay. Sometimes it does and sometimes it doesn’t. Making it home alive and intact, physically if not emotionally, would normally be considered a “win” for everyone involved.
“Everything possible” is way too subjective, wide open for anyone’s interpretation, and not useful at all for the purposes of trying to save people without losing more people, the rescuees or the rescuers alike. In fact, it’s dangerous for obvious reasons. To expect people at the time to accept unlimited and largely incalculable risk on your behalf, or whatever level of risk that you happen to feel is reasonable based on your immediate predicament and level of fear, is just plain unrealistic. To still expect it now is ungrateful, to put it charitably.
As a former search & rescue professional with extensive training and operational experience in launching and recovering small boats from cutters on the high seas, including the North Pacific / Bering / Gulf of Alaska, in all sorts of weather conditions, year-round, day & night, I feel an obligation to warn my brother & sister mariners: think long and hard, and with as little emotion as possible, before ever pulling the trigger on launching a boat or putting any of your crew in the water. It’s easy to underestimate the risks and things can rapidly get away from you. You may never get them back.
That may mean making the decision not to attempt a rescue (beyond what you can do from your own decks) and letting someone, or a whole bunch of people, die right in front of you. That might sound cold-hearted, but it’s not meant to be. Just realistic. My first and biggest obligation is always to my own crew. How much risk I’ll choose to accept on behalf of anyone else depends on a long list of variable factors, including my estimation of the odds of success, in the risk/reward ratio. But in the end it relies mostly on what I estimate are my crew’s collective capabilities with the equipment we have (as opposed to what we’d like to have) measured against how willing they all are. I’m an imperfect human and therefore an equally imperfect master. I don’t want that fact, and my potentially faulty judgment, to get anyone hurt or killed. So I play a conservative game by leaning towards what I judge to be probable, not possible, and what the consequences of a failure may be, as flawed as my judgement may be.
All of my experience thus far has taught me that people usually tend to underestimate risks, overestimate their capabilities, and expect good luck to save the day if all else fails. That doesn’t always result in a disaster, but it sure sets you up for one.