Those unfamiliar with the 'bendy' logic of Mr Ford will be saying to themselves, "Surely the 3rd floor is the best way to hedge your bets, midway between both points. And that way you don't have to create this ridiculous Hoax with all it's
*its*
complexity and unlikeliness, dragging in scores of people to prop up this insanity. Just say the man on the 3rd floor is Oswald."
Glad to see you now accept that the words "I saw a man walking away from the stairway" do after all work for the third floor!

To be honest, as long as he leaves the scene before Truly and Baker it can be any floor you want.
Ah, but the 'investigating' authorities know full well by now that Mr Oswald wasn't just on the front steps at the time of the shooting but had an interaction with Officer Baker at that front entrance. Why, DPD have been telling the world about it!
So the third floor won't work--------Officer Baker and Mr Truly are the ones with the head start, see? How would you get from Mr Oswald at the front entrance to Mr Oswald walking away from the stairway on a floor that Officer Baker and Mr Truly are themselves only just reaching?