Sorry for the late reply. I just got off a 5-day rafting trip on the Yampa river in Utah and I had absolutely no contact with the outside world.
Anyway, I just viewed the video and here is my response:
Playing the video back frame-by-frame, it appears that sidespin is picked up by CB before the 3 moves. This indicates the cushion was hit first. The CB appears to have hit the 3 while still in contact with the cushion, and both balls appear to leave the cushion together. If this were the case, and if there were conclusive visual proof of this, the shot would be a foul. However, it is also possible the CB instead contacted the 3 after leaving the cushion and then returned to the cushion very quickly (too quickly to see with the limited frames of video), in which case the balls would have appeared to move the same way. If this were the case, the shot would not be a foul. Regardless, from the limited video evidence, there is no conclusive proof there was a foul, so the shot should have been called good. I personally think the CB hit the 3 while still in contact with the cushion, in which case nothing was driven to a cushion after OB contact. This would be a foul; but again, the video does not provide conclusive proof that this happened, so the soul should not have been called.
BTW, here is a related shot from the
Video Encyclopedia of Nine-ball and Ten-ball (VENT) showing how a ball hitting the cushion and another ball at the same time can follow the OB away from the rail: