More brutal pedantic nitpicking. Norman confirms right from the start that the shots came from above his head. The only open window above his head is the SN. If you want to believe there is some cause to doubt his hearing the bolt being operated and shell cases hitting the floor, it doesn't make any difference if he still confirms that a rifle was fired above his head. If there were any doubt of this, witnesses saw a rifle in that window at the moment of the assassination and fired bullet casings were found by that window. It's inexplicable how there could be much more supporting evidence of the fact that shots were fired from that window.