I copied and pasted the following from rec.gambling.poker. It’s got no other cite, but he sounds like he knows what he talking about.
Other things posted in that thread (go to google, search on “dead mans hand” and then click on “groups”) indicate that people had the foresight to look at his hand when he was shot.
I also agree – it was a pretty lame write up in the dope column, not up to usual standards.
Here’s the copy and paste. . .
On August 2, 1876, Wild Bill Hickok made a big mistake that cost him his life
but guaranteed his place in the pantheon of American western heroes. Although
he made a point of sitting with his back to the wall whenever he played poker,
on that day, he sat facing it.
Jack McCall, a notorious gambler, entered the rear door of a saloon in
Deadwood, South Dakota, where Wild Bill was playing poker. McCall, who had
problems with Hickok in the past strolled to the bar, turned, and casually
walked to a point where he was just about a yard behind Hickok. Engrossed in
the game and having just drawn three cards, Hickok wasn’t aware of McCall’s
presence at all. Before Hickok had a chance to look at his last card, McCall
drew his Colt 45 and fired. The bullet entered Hickok’s head and exited his
cheek before piercing the arm of another player. Hickok died instantly.
Bill’s friends, who picked up the cards he had drawn, found that he a pair of
black aces and two black eights. Ever since then, aces and eights have been
called the “Dead Man’s Hand.”
While everyone is sure of those cards, there is some contention over the fifth
card in Wild Bill’s hand. The queen of hearts, the queen of diamonds, the nine
of diamonds, and the jack of diamonds have all been cited as the fifth and
final card.
The Old Style Bar in Deadwood uses the nine of diamonds in all of its
promotional advertising, while the Deadwood Chamber of Commerce will tell you
it was probably the queen of diamonds.
But the South Dakota State Historical Society claims the fifth card was not
even in Hickok’s hand at all – it was just being slid across the table to him
when the fatal shot was fired.
So you can debate the exact composition of this hand all you’d like. The truth
is, no one knows. But wherever poker players get together, a hand with two
black aces, and a pair of black eights is called the “Dead Man’s Hand,”
regardless of the fifth card.