Thing is, could the gunman in the SW window see or even know BRW was eating his chicken in the SN? Did the gunman become aware of Williams first or vice versa......tend to believe the former. Williams left his lunch behind and unfinished after he was asked to leave just minutes before the motorcade arrived.
Brennan said that he saw the man who was wearing the light colored clothing move around from window to window ....but was he seeing the same man?? BRW had on light colored clothing and at a glance Brennan could have mistaken BRW for the 175 pound khaki clad man.....It would have been difficult for a man to move from the SE corner window to other windows because of the barricade of boxes behind the SE corner window.....
Could the gunman in the SW window have seen BRW?..... I doubt it......If BRW was sitting on a box in the Se corner many high stacks of boxes would have been between him and the SW corner of the room.....
Did the gunman become aware??.... I believe that the man with the high powered rifle became aware of BRW and put the rifle out of sight while he confronted BRW and told him to get off the sixth floor......and keep his mouth shut about their meeting.
Incidentally....I seriously doubt that there were any shots fired from the sixth floor.....Brennan said he saw the man who was wearing the Khaki clothes AIMING a rifle He did NOT see the rifle being fired.