Any scenario that involved Madeleine dying in the apartment kills the idea of a kidnapper.
It could account for the cadaver odour in the bedroom.
It would not need opened windows and raised shutters, so the claim of staged scene could account for that.
There is a real problem with the logistics of getting rid of the body and hiding it. - still not impossible.
It would not require the twins to be sedated. (Therefore no need to test them.)
No wonder Amaral went with this scenario. Problem is whether Madeleine was alive and well when Gerry did his check. But that observation is negated if Amaral really believes this scenario.
Basic problem is that there is no proof, and Madeleine's body was not found, yet he turns that dilemma around by suggesting a frozen cadaver was in the rear of the Renault, but the DNA result did not confirm that.
But would the doctors do this to their daughter if it was the result of accidental death from a unknown cause?