When Mac pitches the ball to Riley during the final scene, the ball spins. But right before Riley hits it, the ball was not spinning.
In the final scene, Bill Marsh is stopped by a falling scoreboard caused by an impact from a baseball. An impact in one of the number matrices, blowing out a few lamps could in no way have caused the scoreboard to fall. Also, any event which may have compromised the scoreboard's rigging would only have affected a single rigging point, causing it to drop at one end, but it falls with a perfect, controlled vertical fall.
On several shots during the final fight sequence the rubber prop bat can be seen bending.