In part of the video, the tail rotor is turning counterclockwise (as seen from the left side), and later the tail rotor is turning clockwise (as seen from the left side).
Also the tail rotor seems to be turning at different speeds, somtimes very slowly, although this could be due to the effect of slow-motion video.
It’s the difference in frame speed vs eye speed.
It happens is Westerns when they show wagon, buggy and stage coach wheels seeming to turn backwards............
Stage coach wheels did the same trick in old Westerns.
The AI doing the film was having a hard time reconciling with the correct speed.