How do we know that Rosemary Willis, in her conscious reaction to Oswald's first, missing everything shot at "Z-124," had already started looking towards the TSBD by Z-145?
Answer: By comparing the direction she's looking in Z-138 (towards JFK and Jackie) with the way her head and upper-torso are turned to her right in Z-145.


Interestingly, this is about the same time that motorcycle policeman Jim Chaney is looking to his left at JFK (and JFK has turned his head quickly -- and very briefly -- to his left), and Secret Service Agent Glen Bennett in the passenger side rear seat of the follow-up car, having heard "a firecracker," starts leaning to his right to see if JFK's okay.