I think the depiction of what transpired at Parkland Memorial Hospital was shown but only superficially. From what I previously read of that day, I anticipated seeing more hysteria and disbelief from the crowds, which wasn't shown at all; to the astonishment of the doctors & nurses that treated President Kennedy, which lacked a lot. The Secret Service came across as being inept at doing their job to being totally devoted to President Kennedy, even in death.
The innuendo that Oswald was being used or set up played a very minor part of the movie. At the time I watched the movie, I didn't know if the depiction of his mother, bother and his family was accurate. Lee Harvey Oswald's family was never mentioned. After I watched the movie, I did some research and from all accounts the family was accurately depicted.