Illegal Contact?
 

A1 drops back to throw a screen pass behind the LOS to A2. As the ball is in the air, B50 nails A2 knocking him to the ground. The ball falls incomplete. Do we have a penalty? I know it is not pass interference because the ball was behind the LOS. A member of my crew said it is a 10 yrd. penalty for illegal contact. I am unable to find the rule for this.
Thanks for any help!
U52

You have a great defensive play!

The only thing that would matter is if they hit them legally (e.g. helmet contact, blocking below the waist), but they can be hit behind the LOS. They cannot ever be held by the way.

Peace

If the RB is tackled - defensive holding

If the RB is hit as you described - nothing