Look even closer at the Sky Video and you see debris coming from the TR, would also explain the sudden yaw.
You see a dot of something on a very low frame rate video with artifacts from either/both of the compression algorithms of the cctv recording and the sky flash video encoding. I think the low frame rate also makes it difficult to see how it evolves. The other question would be how the shutter speed would capture a (small?) piece of debris from the (high rpm) tail rotor.
even when the CCTV fottage is enhanced
You'll need that stuff from Blade Runner to get a definitive answer from the CCTV frottage.
The left roll could be explained by the not unheard of reversing/whoops TR ding as the lateral drift effect would no longer be present.