In my humble opinion you're full of high-fructose beans.
All I have done is point out the evidence.
Question: How many shots do you think were fired altogether, and how many (if any) were fired from the sixth floor Sniper's Nest?
Again, I can only refer you to the evidence. Here is the distribution of witness recollections as to the number of shots:
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The possibility that the sample mean (3 shots) differs from the actual number is practically zero. This is further corroborated by the physical evidence of shells found (three).
To determine where the shots originated one has to look at all the evidence. When one does that, there is convergence on all shots coming from the same location.
The location is identified by direct observation by witnesses who saw the rifle in the window, by the three witnesses on the fifth floor who heard the shots coming from directly above them, and by the physical evidence found on the sixth floor.