Base, that is irrelevant, as that never happened. That rule tells us the ball is dead on an incomplete forward pass, and the official should declare it dead. It does not say what happens when the official makes a signal on a live ball.
Remember - the play kills the play, not the whistle (except on IW).
I don't know if I could justify the incomplete signal as "signaling the ball dead".
Funny thing, and it says a lot about the state of football today.... I was more concerned that they gave the lost fumble to the lineman, and not Leftwich, as it had an effect on my very close Fantasy Football semifinal game. Sad, really.
