According to the San Francisco Chronicle, the chief questions are the facts that “the coroner reported that the fatal shot was fired less than one inch from Kennedy’s head behind his right ear. Four shots came from the rear but Sirhan fired a .22 from a few feet in front of Kennedy. The revolver held eight rounds, but a radio reporter’s tape recording of the shooting has sounds of what one audio expert describes as 13 shots and double shots.”
Yes, what ONE person said out of several that have examined the recording. And that person wasn't an audio expert. He's a recording machine expert. He had no good science backing up his opinion.
I had a high school class with Sirhan Sirhan in Pasadena, California. I spoke with the history teacher later - S2 was quite involved in class discussions about the Constitution/ Senate etc. Nothing aberrant but definitely on the intense end of things.