Friends, let us imagine (purely for argument's sake) that neither Mr. Truly nor Mr. Shelley knew of the plot beforehand. In all innocence, they hired a team of carpenters to come in for a big floor-laying project.
The assassination happens. Once it is established that everyone in the internal floor-laying crew left the sixth floor for their break, Mr. Truly and Mr. Shelley realise in horror who must have carried out the assassination.
Do they
a) tell the authorities all about this crew?
b) keep schtum (out of personal fear of reprisal and of being arrested for complicity), and get the internal crew to pretend they and they alone had been doing the floor-laying?
And once Mr. Oswald is singled out as the prime suspect, do they
i) defend their man, even at the risk of drawing heat on themselves?
ii) let him be fed to the wolves by doing all they can to help the authorities' ridiculous LN narrative?
Now! Continuing with this working premise that Messrs. Truly & Shelley did NOT know the true intentions of the outside-contractor 'floor-laying' crew beforehand.....
Let us assume (again for argument's sake) that Officer Baker's 11/22 account of what happened in the building reflects actual events:
Let us put ourselves in an innocent Mr. Truly's shoes for a moment:
----------At first, he doesn't think the shots even came from his building
----------But he runs in and offers to show the policeman up the building
----------Several floors up, the officer catches a man walking away from the rear stairway
----------Mr. Truly recognizes the man as one of the outside crew that has been working on the floors upstairs, and tells the officer that he's okay, he works here
----------Later on, Mr. Truly puts the pieces together: that crew were not what they seemed, and that man by the rear stairway was making an escape
What does Mr. Truly do ?
a) Tell the authorities the truth about the encounter, and thereby reveal the presence of an external crew?
b) Find a way to keep a lid on the external crew's existence by keeping the incident in-house, i.e. pretending the man challenged by the officer was in fact an actual Depository employee?
But which Depository employee? Well, for starters, it would have to be a man who bears at least a passing resemblance to the carpentry-crew man caught walking away from that stairway......................
Imagine----------------for example-----------------this light-brown-jacket-wearing man was the actual man described in Officer Baker's affidavit:
He looks rather like Mr. Oswald. Might Mr. Truly get away with a switcheroo?