[Adam]

I'm not sure I would go with Flagrant, but I wouldn't lose sleep over it if my partner did it. If I was on the floor where that official is standing, I would have a better view of the defender and any "follow through" or "wind up."

All that said, intentionals can be called for either "intent" or "excessive contact." It jibes easily, since the rule says they "are not based solely on the severity of the act." That's making the point that you can call an intentional foul even if the contact isn't severe; the final sentence gives you license to call it on a play like the OP video. This way, when a player makes an attempt to go for the ball but knocks the player into the bleachers, you can call an intentional foul.