At this stage it looks to me as if the snippets of "witness reports" we are informed of are worthless. The real witness reports are being kept under wraps.
I was unfortunately around for a completely different crime event many (30+) years ago (OK, I spent my teens in Laurel MD and was in the shopping center when George Wallace was shot, only about 50 feet away).
People get excited, memories are blurred, adrenaline is running, and there seriously is a lot of trauma and general chaos, people want to talk with someone to get the chaos out of their minds, and that would usually mean to reporters and the police.
I can understand why someone would pass along anything they see (or imagined they saw) as being "relevant", because you want to be as helpful as possible. But I cannot understand why anyone would fabricate a story from whole cloth. Honestly, it doesn't compute. It's almost perverse.