you could have done more damage to the camera by launching a bullet with a decent slingshot.
I seriously doubt it. The area on the top-plate is totally tweaked and penetrated. You're probably not going to do that with a slingshot other than one of those crazy ones. While I don't disagree that the bullet probably wouldn't have killed him if it had slowed down by that point - but the point is his camera took a bullet while in the process of documenting a war. No reason to minimize that or get pedantic over it.