Yes, I've always wondered about that. He's banking on the noise alone and the other clues (broken window, bullet in the wall, his words) to sell everyone on the story and perhaps, overlook the scraps of paper which may or may not have blown away off the outside deck. I've also wondered how loud a firecracker would actually be and would it sound much like a gun shot. Not being a ballistics expert, I'd appreciate someone in the know to offer thoughts on that, too.
I don't know guns, but it seems like I always hear that nothing else sounds just like a gun firing a bullet, including one firing blanks. In fact, you actually hear that in a Columbo episode, but I can't think which one (Playback?).
Yes, it was PLAYBACK. Columbo fired the bullet into the box of sand. Harold asked him, "Why not just use a blank?" Columbo replied, "Doesn't sound the same. Never does." Or something like that. I wouldn't know, either.
Yeah, i agree it was a stupid move by Heyward. I can't recall, but was Columbo closing in or Heyward just getting paranoid? I know Columbo asked a sergeant to let him know if Heyward goes to his office alone so he was sniffing something out.