A 747 at take off has an eye watering amount of inertia, it takes time to do things.
I got that. .
Once it was yawed right from that wing drop it was game over - the knife edge turn basically put it in free fall from 1200' with bugger all energy.
Also got that.
I still don't see how that's a spin, but I think I can piece together how what you are describing is similar to a spin entry. *scratches head* As the nose drops and the wings level, it appears, from what little we see, that it is still in a stall but it does not appear to be rotating about the vertical axis (again, the view may inform this impression) which is what I associate with a spin.