My initial reaction, after watching the video, was that the combination of the angle of the shot (making "push" less likely), the significant elevation of cue, and the use of a short stroke that just didn't have the appearance of a stroke capable producing a double hit or push, all added up to a legal stroke. I was actually pretty surprised by the number of responders saying that they thought the shot was a foul. So I went back and looked at the movement of the cue ball relative to what the tangent appeared to be, and even after giving what I thought was considerable benefit of the doubt as to where the tangent line might be, I started to think that there was no way the cue ball had not crossed the tangent line. I then I stopped my lean in the direction of concluding that that there had been a foul when I had this thought: how much room is there between the cue ball and the object ball? If it is even a little bit more than what one might think -- and remember, we have only one camera angle -- that really changes what the tangent line possibilities might be. How many times have you watched a video of a match and thought, based on the first camera angle, that a ball didn't have a lane to a pocket, only to be really surprised to see, based on another camera angle, that the ball easily had a path to the pocket? So, I think that the apparent certainty on the part of some responders about where the tangent line lies is a bit unfounded. Bottom line for me -- it might be a foul, but we can't really know.