1) Really? This sounds completely implausible to me as I don't believe for a second an alarm could be ignored by cabin crew for 16 seconds let alone minutes, but assuming this was real, I'd personally say basically being told you are about to die and then it not being corrected for 16 minutes is cause for serious compensation. I would be utterly furious!

2) Is it really that shocking to you that some people panic and don't think things through while they're facing almost-certain death (which is what I'd assume a water landing in the middle of the Atlantic would be)? It's not simply a case of the safety briefing mentioning it - it's also common sense. Rational thought isn't always available to people in scenarios like that though - especially if they can't swim. Maybe the risk of getting stuck in the plane could seem less worrying to them than the thought of sliding into the Atlantic Ocean with nothing to keep them afloat?