The vignetting effect in the videos is typical of copyright material uploaded to YouTube in an attempt to bypass automatic copyright take down programs. Pretty much the whole Air Accident Investigation series is displayed in this format along with several similar series. Quite possibly the video is a clip from one of these many programs.
A loud bang at the end of any CVR playback would be expected whether it was a bomb or an explosive decompression as the tail broke away from the aircraft. Not conclusive proof that an explosive device was involved, in the absence of other corroborating evidence such as explosive residue and recovery of components near the centre of the blast, allowing particle trajectories to be calculated.