I have about 130 hours in a ASW Mi-14 and one of the systems on the aircraft is a door, window, radome, and bomb bay pneumatic seal that is supposed to be activated anytime over water. If the system is not activated, the radome will fill with water when you land in the drink and at 8.5 lbs. per gallon the weight it takes on will preclude any kind of take off. There is simply no way that enough aft cyclic control is available to stop the nose down pitching moment. Also, notice that the sponsone floats were inflated at some point which will allow for some lateral water stabilty, but not help a bit with pitch control. It appears that the seal, if installed and working was not operating since in one frame the left door is partially open. The pneumatic system seals all of the aircraft doors/openings at once.
I suspect that once she went into the water, it didn't matter what the crew did. The nose was going down.