Last shot question

[doghead]

NFHS Question:
Scenario: Girls' HS Varsity Scrimmage. Three person mechanics. Ten seconds left to play. Ball is in B's frontcourt. I am the 'C' (therefore I have the last shot). A1 steals the ball with 2 seconds left, guarded by B1. I'm still 'C' with last shot responsibilities. A1 goes up for the lay-up on the buzzer but does not release in time. I immediately indicate "no good". At that very moment I hear my partner's whistle (Lead) for a shooting foul. Uh-oh!!!

I ask my partner if she did not see me indicate "No good". She said, "Yeah, so, I can still have a shooting foul". She lined the gal up and gave her two free throws.

Is this possible? Help me out here. Thanks.