HH,
The lower the float time, the harder it is to get insurance (ie more expensive and higher excess for water operations). With the higher hull value and passenger numbers that go with the larger aircraft, float experience makes a big difference whilst turbine time doesn't. On the same token I do know of two pilots that got their first gig in vans - one had significant total time, the other already worked for the company.
Bla bla bla,
Apart from the outcome (aircraft inverted following a landing on water with the gear extended) I don't know what happened in that accident - and I'd be surprised if you do either. There have been NUMEROUS cases around the world where amphibious pilots have extended the undercarriage whilst doing their pre landing checks for a water landing. Unlike a land plane, the gear configuration changes depending on the surface - and green is definitely not safe. As distraction at the wrong time can result in disaster a disciplined set, check and challenge procedure executed religiously as the primary thought processes is essential. I would have thought that the change in performance with the Dunlops hanging in the breeze on a longish sector would be very apparent.