As would be expected when the shooting started people were running outward toward the stores hoping to not get hit. I get the impression that after the hero knew he hit the shooter, the shooter started retreating to the bathroom and Eli finished.
I think you are right about the shooter never expected to be trying to defend himself. Maybe not even sure at first where it was coming from which gave people time to get out of the line of fire.
one of the witnesses leaning against the entry of Dicks said he ran into the store but wasn’t even sure if he was making the right decision. He was hoping he wasnt disoriented as to where the shooter was.
I have never been in a situation like that but I am in awe of what the Hero did. Just the disorientation factor and having a GF beside him he was trying to protect and telling her to get down while he was trying to pull his gun