With "bring it on" in mind, just how does Zapruder and Sitzman fit into these alleged shots being fired Only feet behind them? They have Never said they heard shots being fired that close to them. Tink Thompson Q/A'd Sitzman regarding someone firing a rifle in close proximity to her when he interviewed her for "Six Seconds In Dallas". She denied HEARING/seeing anyone firing a gun in that general area around her and Zapruder.
Again, for the nth time, Zapruder heard shots as he thought he was in direct line of fire in his TV interview. He even went further in his WC testimony that the shots came from behind him. This is what is verifiable. As for your other questions, you are probably better off asking a psychologist about why Mrs. Sitzman did not hear anything except for a really loud report caused by a soda pop bottle that a black couple had and that no-one can verify. She also says that after she got off the pedestal, she went down near the street and spoke to someone, when the Bell film shows that she never did go down to the street level. Yep, a psychologist might be able to help. I am not a psychologist, so I can't help.