I have the same problem, and it also happened to me in another scene (can't remember which one). I think it happens because I use the Space Bar to read the dialogues instead of clicking, and once I reach a scene with choices, the Space Bar might do some weird stuff like "going to the next dialogue without picking either choice," which causes the end of the scene and leaves you stuck like that image. At that point, I could only close the game and redo everything. It wasn't a big deal the first time thanks to the auto-save, but since you can't use it during the last part of the game (and during what I assume is the last scene), it was really annoying.
I'd like to confirm if
envy5 did something similar.
I hope this information is useful in some way. Keep working hard (no, I am not being sarcastic btw).