~Grin~
So what? The man with the rifle was highly significant to Mr. Rowland, at the time and then even more so in hindsight. The unarmed 'elderly Negro' (bald, bright-plaid-shirt-wearing) not so much.
But nice try!
Here are a few more. As you can see, we humans do not have instant replay memories that get all the details accurately every time. If Arnold Rowland really thought he saw a black man in the southeast corner window, I believe that he could have seen one of the ones on the fifth floor and misremembered it as being the sixth floor.
Mr. BELIN. Did he say anything about any other people in any other windows?
Mrs. ROWLAND. No; I don't think so.
Mr. BELIN. Now, did you notice any other people standing in any other windows or leaning out?
Mrs. ROWLAND. I am not sure if I did at that moment.
Mr. BELIN. Later on?
Mrs. ROWLAND. I saw some people either earlier or later looking out the windows.
Mr. BELIN. Do you remember anything about any of the people you saw?
Mrs. ROWLAND. Some of them were colored men. I don't think I saw any women.
Mr. BELIN. Did you see any white men?
Mrs. ROWLAND. I am not positive.
Mr. BELIN. Do you remember where you saw any of these Negro men?
Mrs. ROWLAND. On a lower floor, about the fourth floor, I think, and nearer the center window. The windows nearer the center.
Mr. BELIN - Did you see any other people on the sixth floor?
Mr. EDWARDS - No.
Mr. BELIN - Did you notice whether or not there were any, or just did you look and see any?
Mr. EDWARDS - I notice that there---I just didn't see any.
Mr. BELIN - What about the next floor above? Did you see any people on the floor above?
Mr. EDWARDS - No.
Mr. BELIN - What about on any floors below? See any people on the fifth floor?
Mr. EDWARDS - No.
Mr. BELIN - Fourth floor?
Mr. EDWARDS - No.
Mr. BELIN - Third floor?
Mr. EDWARDS - Possibly.
Mr. BELIN - Second floor?
Mr. EDWARDS - I believe so.
Mr. BELIN - First floor?
Mr. EDWARDS - I don't know.
Mr. BELIN. Did you see any other people in any other windows that you can recollect?
Mr. BRENNAN. Not on that floor.
There was no other person on that floor that ever came to the window that I noticed.
There were people on the next floor down, which is the fifth floor, colored guys. In particular, I only remember two that I identified.