The distances being travelled were not very far, you make out like they were trying to climb Everest!
By taking the following path from Haywood's bike to the first time he's seen in Darnell, is at the most about 60-70 yards.

And the distance for Walthers to basically walk down and cross the road was about the same. If the time stamp was less than 12:37 then we might have trouble but every established event happened in chronological order and with enough time between to account for travelling!

Mr. WALTHERS. And at that time I heard the shots as well as everybody else, but as we got over this fence, and a lot of officers and people were just rummaging through the train yards back in this parking area.
Mr. LIEBELER. In the parking area down there? West of the Texas School Book Depository Building between the Texas School Book Depository and the railroad tracks?
Mr. WALTHERS. Yes; and the discussion came up among several of the officers, "Were there any shots fired?" And I said, "Well, they sounded like rifle shots to me." At the time no one knew---in our crowd they were sure the shots had been fired though because of the reports---we heard the noise, and I left then and went back up here and came back onto the street.
Mr. LIEBELER. Up on Elm Street?
Mr. WALTHERS. And went over on this grassy area right in here [indicating].
Mr. LIEBELER. Between Elm Street and Main Street?
Mr. WALTHERS. Between Elm and Main and starting to looking at the grass to see if some shots had been fired and some of them might have chugged into this turf here and it would give an indication if some had really been, if they were really shots and not just blanks or something, and a man, and I couldn't tell you his name if my life depended on it---he had a car parked right here in Main Street---in the Main Street lane headed east, just under this underpass.
And as seen everyone was walking with some pace, it wasn't a Mother's meeting, they all were trying to find something, anything! But alas there was nothing to be found because all the action happened on the 6th floor of the TSBD and this is supported by ALL the evidence from the ballistic evidence through to the medical evidence.

JohnM
The major problem with your story is that Haygood NEVER Testified that he made 2 separate trips back inside the railroad yard. Never! And why if his intended destination was the TSBD loading dock, would he go ALL the way back inside the railroad yard? He could have just exited the parking lot, hugged the Pergola, and then straight across to the loading dock/Houston St. And the 1,000 lb gorilla in the room is why Haygood would not just use his motorcycle to reach the TSBD loading dock off of Houston St? Why would Haygood climb the grassy knoll AGAIN, scale the Triple Underpass AGAIN, or climb over the picket fence, and then go deep into the railroad yard? Why not just use his motorcycle?
The Darnell Film clip you are using is why I asked you to check with Steve Barber regarding what the motorcycle cop is holding in his (L) hand. All things being relative, that Darnell copy is wanting. This limited definition is why you think he is holding a glove. Your seeing things blurred. And, I your copy has been sped up too. Watching it is kinda comical. It has a "fractured flickers" look to it. Buster Keatonish during his silent film years.
Barber previously posted a Darnell still frame, (now MIA), that had very good definition. The still frame he posted was a frame from the sequence where the motorcycle cop was walking past Officer Harkness. The motorcycle cop's (L) hand and whatever was in it was visible in that still frame. Maybe Steve has other Darnell still frames showing this (L) hand? The 2 of you might be able to figure out what is in that (L) hand by examining numerous frames? At a minimum, he can tell you what he see's on his Darnell copy,