SaSless,
many a true word spoken in jest!
I was touching on a burden of knowledge point earlier on when I suggested the operator should have been able to foresee more or less what happened here.
Something snagging a control : excited passengers moving around, assorted attachments and lanyards, key controls on the floor : Reasonably foreseeable
Emergency landing on water : densely built up area under much of flightpath, water under much of the rest: Reasonably foreseeable
Aircraft doesnt float upright on landing : difficulty in achieving a smooth autorotation, history... : Reasonably foreseeable
Passengers trapped in aircraft : Upside down, cold shock, need to use knives/ unshackle harnesses. (lack of doors a mitigant) : Reasonably foreseeable.
Simply my opinion of course, but whatever way you look at it, I dont think the operators would have had to spend too long thinking about it to imagine that a scenario like this was a possibility in the event of an aircraft emergency.