But the whole exercise is so repeatable. Anyone with a similar type window could test it at home. As long as the window is slid shut rather than locked and the window that opens is near to the pull apparatus that raises the shutter. Then it is possible to raise the shutters from the outside by reaching to the inside.
The whole exercise is only repeatable at accurate full scale model level. Or on site.
All that has been proved is that under certain conditions of which we have not been fully appraised the window can be slid back and a pillow passed through it. Without taking into consideration dead weights and positional relationships it has been decreed less or more oh yes that's how it was done. Conclusion reached and cast in stone on half a tale.
I am give or take 1900 tall. I can reach an object with both hands approximately 1000 in front of me provided it is at waist height. I doubt I could dead lift the equivalent of a car battery at that distance from that height.
Hint as I have posted before: have a look at bloody good test book on ergonomics it is relevant If you don't think it is you will come up with the wrong result.
This little "window scenario" rapidly becomes a conspiracy theory because no one seems willing to look at the venture as whole under all the conditions that would have obtained at the time.
Certain assumptions have to be made about the construction, attitude and aspect of the window.