Illinois vs Michigan State Foul On Free Thrower (Video)

[Nevadaref]

Let's put this play in an NFHS game and say that the contact did occur after the ball passed through the basket.
Now we have a rule which tells us to ignore contact during a dead ball unless it is deemed intentional or flagrant.
What do you guys think is the right standard for making that determination?
Do you use Terry Wymer's "in an unnecessary manner" to judge the contact or would you consider if the contact happened during a live ball and ask yourself if you would call an intentional or flagrant personal foul? I think that the mindset with which we examine such things can render different conclusions.