O'Donnell doesn't seem to merely "go along" with a "narrative"; in 1964, he's laying out the rationale for what he heard:
Now O'Neill said he got Dave Powers to "confirm" the meeting but we don't know to what extent. Powers himself was a "shot from the front" fellow, suggesting the Underpass:
Oh, no! What do we have without O'Donnell and O'Neill?
We have all of this:
The radio log states that when the assassination occurred, Curry, who was driving the lead car of the motorcade directly in front of President Kennedy’s limousine, stated, “Get men on top of the underpass, see what happened up there, go up to the overpass.”
Dallas County Sheriff Bill Decker and Secret Service Special Agent Winston Lawson, who were also in the lead car, further bolstered Curry’s adamant view about shots originating from in front of President Kennedy.
As soon as Curry issued the instructions to “get men on top of the underpass,” Decker stated, “I’m sure it’s going to take some time to get your men in there. Put every one of my men there. Notify Station 5 [Sheriff’s Office] to move all men available out of my department back into the railroad yard and try to determine what happened and hold everything secure until homicide and other investigators can get in there.”
Secret Service Special Agent Winston Lawson wrote in his Secret Service report on November 23, 1963, “Chief Curry gave instructions over his radio for officers to converge on the area where the incident occurred.”
There is no ambiguity in Lawson’s report, as the radio log clearly states that the area where Curry instructed his officers to “converge” was “on top of the underpass.”
Secret Service Special Agent Forrest Sorrels, who was in the lead car, wrote a report stating, “When I heard two more shots, I said ‘Let’s get out of here.’ I looked toward the top of the terrace to my right as the sound of the shots seemed to come from that direction.”
He testified to the Warren Commission that he “did not look back” at the Texas School Book Depository “because it was way back in the back.”