I was there. Stall. Definitely. The wing dropped likely because it was an asymmetric stall/beginning of a spin, likely due to her additional weight on that wing.. (pure speculation of course) Also note, though very hard to see in the videos, right as the plane rolls inverted, there is quite a puff of smoke from the exhaust, which was much more plain in person. They had not been running smoke system at that point in the act (if at all) so I dont believe it was that. I believe (again speculation based on what I saw) there was an engine malfunction of some sort (just as they rolled inverted) which led to a stall, and the wing dropping (heavy side, with Jane's weight and additional drag, causing it to stall first). This i believe because if you notice in the video, the ailerons are deflected opposite of the roll, indicating an instictive reaction to counter an unwanted roll.
Again, speculation, but that is my belief based on my presence, and the video.
