So what is being suggested? I'm not exactly sure why all this matters.
You're not sure why it matters that Bonnie Ray Williams had his lunch sitting in the Sniper's Nest while a man with a rifle was stood at the other end of the 6th floor? You're not sure why that matters?
We know with absolute certainty that at 12:30 someone (i.e. Oswald) was pointing a rifle out the 6th floor window. So someone was there at 12:30 whether BRW saw or heard anything while having his lunch.
We know it wasn't Oswald as four eye-witness reported that the assassin was wearing clothes Oswald wasn't wearing that day and didn't own.
We know it wasn't Oswald as he never had the distinctive bald spot Amos Euins was adamant about.
Not to mention the report of Oswald's observation of Norman and Jarman as they made their way to the west elevator after entering the rear door of the TSBD building.
But someone was definitely pointing a rifle out of the SN window and they fired the rifle from the Sniper's Nest, vacated by BRW minutes before.
It seems extremely unlikely that BRW would have seen or heard anything suspicious and never mentioned it to anyone. And would go to the window directly below if he had reason to believe something was up on the 6th floor.
Does it seem likely that a young black man, in Dallas [the City of Hate], in the '60's, would lie to the police when questioned about the assassination of the President? Because that's exactly what he did.
And when he did admit to being on the 6th floor he continually lied about how long he was up there.
And he was still lying during his WC testimony when he said he had his lunch in the place the Crime Lab photographed his lunch remains. We know this because his lunch remains were found on top of the SN.
Williams consistently makes every effort to distance himself from the SN.
If he saw anyone on the 6th floor before coming down to the 5th floor to join Norman and Jarman, it wasn't Oswald, it was someone still very much alive at the time of his WC testimony. Otherwise there would be no need to continue lying.