I can find almost nothing in the Warren Commission?s conclusions that I disagree with. Just the last line.
(f) Within these limitations, however, the Commission finds that the agents most immediately responsible for the President's safety reacted promptly at the time the shots were fired from the Texas School Book Depository Building.
However, the reasons for the slow response of the Secret Service are easy to see. A motorcade with frequent loud backfires by the escorting motorcycles is bound to slow their responses. The backfires would be about as loud as a rifle shot, particularly with some motorcycles being so much closer to the Secret Service agents then a rifle 130 to 265 feet away.
I think it is natural to except most Secret Service agents to not begin to react until after the President is wounded at z222 and for the two agents in the front seat, who did not see the President?s reactions to his wounding, to not react effectively until after the headshot at z312.
The Warren Commission conclusions were much sounder than the later House Select Committee on Assassinations. I think this shows the pitfalls of having a later investigation designed to find errors in the first investigation due to a possible lack of time. The desire to find major errors in the first investigation caused the HSCA to make major errors in their conclusions.
The reactions of the Secret Service were not overly delayed if the first shot occurred at z210 as the Commission seemed to find. Certainly that was McCloy's position because he made the point that Connally was struck by it but didn't notice it until after the second shot.
With the cars going down Elm and about to enter the freeway, there was not a lot that could be done. JFK did not want SS agents on the back of the Presidential car.
Clint Hill saw the opportunity to reach the President's car when it slowed down just before the head shot. He jumped off the followup car within about 3 seconds from z210. Jack Ready on the right front running board started to run to the President's car immediately after but was called back by Emory Roberts for safety concerns (CE1024, 18 H 734 and 750).
In retrospect, the SS agents were not adequately trained to recognize gun fire and to react. If Greer had been able to recognize the gun fire at the first shot and immediately react by making the President less of a target - and certainly not slowing down to make him a sitting duck - the result might have been different. But that was a training issue and it is unfair to put the blame on the agents themselves. Even if the other agents had recognized the first shot as gunfire, there was little they could have done in the 6 seconds that followed. Six seconds is not much time to do anything let alone determine where shots are coming from and put your body between the shooter and the President, which was the best they could have done.