The fatal crash video is of an ex military Cessna Bird Dog, which was nowhere near its service ceiling, nor its MAUW. The crucial last bits of the tape were damaged. The wreck was not found for a long time. Cause of the steep right bank??? Katabatic downdraft? Control failure?
Going close to the right slope would be normal before a left turn, which he had plenty of room for.
This video should never have been released by the US agencies trusted with it.