The shot was wired. No smart player is going to open the rack wide open against someone that can run out the game unless he knows the ball is going in.
It just happened to lie as one of those shots that look super impressive, but, like a trick shot, is actually hard to miss. I set it up on my table, cajoled my wife, who does not play more than one or two racks a year, to shoot it, and she made it after I told her where to hit the rail.
That's not taking anything away from John. One has to know how to spot those type of shots, and be able to determine if they are dead, or just close, or iffy. This one was dead wired. It's all about knowing tangent lines.
Notice the safe John did at 2:50. He was setting up the possibility of that shot. The commentators were wondering why he didn't go up table with the cb. He didn't, because he wanted Thorsten to bring it up table for him. First thing John did is go look closely to see if he did get it set up to go. When he was sure it was wired, he fired it in.