None of those windows were modern. Even the fanlight would have had a " screw-down " lock. The system then seemed to have been more foolproof than now.
Windows would have to be broken in order to get to the locking system.
Very few windows are broken today to gain entry as thieves have got the modern way off to a fine art.
I agree about those windows lookout, I grew up in a house with casement windows, it was impossible to let the bottom lever fall into place. It would land anywhere except where you wanted it and if it did land in the right place it still needed to be pushed down to lock.
If the top window was large enough you could stand on the outside sill and lean in and lock the side lever but it was impossible to reach the bottom without falling head first.
With an implement shaped the right way you could lift the arm up but cannot imagine anything which would be able to pick up the lever and push it into place.
The only way would be to use some kind of implement, however, it would be very difficult if at all possible to fashion. For all that such a thing may exist and could have been used. That small fan light window was so narrow no one could have leant very far in to lock anything without an aid.
