I have a very specific question:
In a building where you have two doors on opposite sides both of which can only be opened from the outside electronically (from the inside you can push them open). You're on one side and a Jew is on another side. The Jew on the other side opens the door on his side electronically, walks in, and then opens the door on your side.
Is this considered getting benefit from a Melacha on Shabbos? The act that you benefit from is him opening the door, which is not a melacha, but this act was only possible because of the melacha he did first.
I'm seeking not a practical halachic ruling about my specific case but any sources or logical arguments that may touch on a question like this.