Adverse, I'm sorry gut your reasoning is fatally flawed. All that would be required to cause a forced landing would be sufficient water to stop the engine, plus a lttle bit more to thwart one, maybe two restart attempts.
Your reasoning assumes that the engine carries on processing the contents of the fuel tank at an unchanged rate after an engine failure, which is patently not going to be the case. Even with a windmilling prop and a normally aspirated carbureted engine, there is far less suction to cause fluid to be drawn from the carburettor. In fact the amount of fuel/water drawn would be tiny.