Very shortly after the event, I remember one or two news reports saying the rifle was left in the car. All later reports I saw were that a rifle was used.
News organizations sometimes get information wrong when they're rushing to report on an event. That's not evidence of a lie or of a conspiracy.
“Australians have very bad habits – piracy happens to be one of them.” --News Corp CEO Robert Thomson, on Game of Thrones torrents
Dreams and schemes and circus crowds...