Since the flightpath relative to the ground is visible in the video, it is possible to construct a flight-path vector (at least approximately) for each frame. So one
can make a pretty good estimate of the angle of attack, based on the video images and some simple geometry.
E.g. this picture taken from the video shows the aircraft shortly before impact, with the aircraft slowly descending:
The angle of attack shown in that frame would have been slightly larger than the pitch angle.