Most of the float planes in Puget Sound are 50 years or more old.
This wasn’t some weekend hobbyist out flying either. It was a commercial operation with a good record from what I have heard.
Flying low and slow and running into an unusually strong wind shear could easily drop you out of the sky.
How low? Not 16 feet above the water? Safe altitude 2,500 feet above the water? Operate mostly single pilot no co-pilot? DHC-3 Otter has autopilot? Did any similar incident happened before with float planes flying in the Pugget Sound?