A friend of mine saw the Darnell film at the Researcher's Room a few months ago, and he saw the film taken from the top of the knoll. That seems to contradict your observations.
Denis, thank you for that info. Recently I decided my initial impression was not correct, and indeed the girl running down the hill is part of the Darnell film. I based my earlier conclusion from the very last second of that clip. In the museum's film that last second or so shows a tanker truck entering the frame in the center lane of Elm. I had not seen that tanker truck in any previous versions of that clip. I'll have to add this to my list of corrections.
By the way Denis, I used your compilation for a visual aid. I'm not sure that it is your latest and greatest version. If you would point me to your best version I'll update the link.