Bill James is a smart guy. He's more responsible than anyone else for "sabermetrics," a.k.a. the logic reasoning-driven re-thinking of the game of baseball that's been going on for the last two decades. He also believes that a Lee Harvey Oswald, acting alone, planned and carried out an attempt on John F. Kennedy's life in Dallas 50 years ago that ended with Kennedy's death. In other words: Bill James, not a conspiracy theorist or a loon.
He does, however, have a very interesting theory about why Kennedy actually died. More to the point, Bonar Menninger and Howard Donahue have the theory, which is laid out in Menninger's book Mortal Error. James enthusiastically endorses the theory in his own book Popular Crime. (Popular Crime, James' obsessive study of pretty much every notorious American criminal case of the last three hundred or so years, is highly recommended.)
So, Howard Donahue was a ballistics expert hired by CBS in 1967 to research the assassination. He came to believe that Oswald shot at Kennedy twice, missing once and hitting Kennedy and Governor John Connally with the other shot. But Donahue thinks that the bullet that killed JFK was fired by accident by a member of the Secret Service in the car directly following Kennedy's limousine.
"I have read Mortal Error carefully, and I have to tell you, if there's a flaw in his argument, I don't see it," James writes.
It's a detailed argument, obviously, but it boils down to this: Kennedy's fatal wound seems to have come from a bullet fired on the same plane as his head (rather than above). Secret Service agent George Hickey, in the car trailing the president, picked up an AR-15 rifle immediately after hearing Oswald's rifle shots. (See the picture below.) Another Secret Service agent in fact said in a statement that, on that day, he'd thought Hickey had fired his weapon. And several witnesses near Hickey's car reported smelling gunpowder immediately after the shots. Donahue therefore believes, as Bonar Menninger writes in Mortal Error, that Hickey fired the kill shot by accident.
The Hickey theory was revived this year in a movie called JFK: The Smoking Gun, which apparently makes a further case for a post-killing coverup. It should be said that Hickey sued St. Martin's Press for libel when they published Mortal Error and received a monetary settlement, although St. Martin's has not withdrawn the book or its claims. And for a good critical look at Donahue (and JFK: The Smoking Gun), check out this piece. (Most obviously: why didn't anyone near Hickey's car report hearing or seeing a guy accidentally kill the president with a machine gun?)
Anyhoo, who knows. Ultimately the only true conclusion that can be drawn from the JFK case is that finding an objective truth is, if not an illusion, at least an impossible dream given our meager human tools, and that we can no more know what "really" happened in Dealey Plaza than we can know whether there is an afterlife or why we exist.
But still, if a Secret Service agent really killed Kennedy by accident, wouldn't that be totally crazy? Baseball!