Backward Pass...or not.

[Rich]

Originally Posted by Redding

It is also a forward pass if a defensive player contacts the ball or the passer after forward movement of the passer's arm has begun, regardless of which direction the ball actually goes (2-31-2 Nt). Once the passer starts his arm forward, it is a forward pass regardless of which direction the ball leaves his hand or where the ball lands. The passer receives the benefit of the doubt as to whether the ball is thrown or fumbled. When in question, rule it a forward pass, and not a fumble.

In other words, in the OP was the arm coming forward when B-90 swung him around?