These are very valid questions and I am sure the that the same or similar questions have to be answered by the company once the investigation begins.

It should be noted that the aircraft is a Grumman Goose and is amphibious and can set down in water in case of minor mechanical problems. Consider that the area where the plane went down is surrounded by water, the company may of initially thought that the aircraft set down with this scenario in mind....just my WAG.