Let's make a deal; you provide me with evidence that Oswald or anybody else stuck his head and torso out of the 6th floor window of the TSBD, just minutes before the motorcade arrived, and I will show you a video that even then that person still couldn't have seen the sidewalk running directly next to the building.
So, let's have that evidence..... Oh wait... I forgot for a moment who I am talking to.
The normal procedure is to run tests first to see if is doable in he first place, such as did the subject use a hand-mirror to stick out the window at some point, for instance. After all, lots of ladies to powder their noses and misplace their hand mirrors.
I forgot for a moment who I am talking to_YOU don't talk TO anybody. You talk AT them
stuck his head and torso out_No torso required. Just head and neck.
Torso needed later for when Oswald gets what he deserved.
Meantime
The ledge barely clears the building. No peering-down issue there.
Nothing to stop a willing participant from snuggling up to the brickwork, taking a knee,
and flopping forward for an easy peer over the edge
So what's the problem?