It is possible to fall into a window.

[aterweele]

This seems like it should not happen, because I don't think it's normally possible to move into a window.

I was able to move out of the window.

[anaseto]

Yeah, it should not happen. It's quite weird, because there's no special code for falling vs descending stairs with respect to player starting position, as far as I remember. I'll need to have a closer look at the code.