In the pic below I've boxed off what I thought were the right raised arm of Lady#2 and her left lowered arm.

No, here's what you actually wrote (emphasis added):
In the pic below the woman you identified is in the orange box.

You mistook the woman's raised right arm for her face.
Just before this, you had written, with reference to Towner, "we should be able to see the woman dressed in black, with her arm raised, waving something". This was a poor assumption, because it failed to consider that
from Miss Towner's POV Lady #1 (lady in black) would be blocked from view by Lady #2.
**
Now let's cut to the chase.
When the flag in Towner is at higher elevation (last frame in the sequence below), it shows BEHIND the man in khaki's head. At this same precise instant, there is nothing------nada, zilcho-------by way of fluttering/waving object visible behind that man's head in Bell. The fluttering from the lady in black's hand is NOT anywhere near far enough west to go behind the man's head, such that it will show up in Towner behind his head. In fact, we can clearly see the white stone of the window grid area back in the TSBD behind both of them.

Therefore, the fluttering coming from the lady in black's hand cannot possibly be responsible for the waving object we see in Towner. That waving object is coming from the west part of the doorway, and the person responsible for it is a man in a red shirt who, in pumping the object up and down, is energetically putting his body into the action:


In your solution--------

--------you mistook the flag for Lady #1's hand, and the man's red shirt for her raised right arm.
The good news is that you can undo this error in an instant by no longer mistaking the flag for Lady #1's hand, and the man's red shirt for her raised right arm.