Somerville, N.J. ? Jayson Williams told a defense expert he “chugged” up to 18 ounces of Scotch after he killed his limo driver — a scenario that would explain why his blood-alcohol level was so high eight hours after the shooting.

But so far, no one who was in the retired New Jersey Nets star’s rural New Jersey mansion early on Feb. 14, 2002, has testified to seeing Williams drink as a state police investigation into the shooting was unfolding.

Instead, testimony at his manslaughter trial, which was postponed Monday due to the death of defense attorney Joseph Hayden’s mother, has presented details of heavy drinking by the ex-athlete during the four hours before he fatally shot Gus Christofi.

The first claim that Williams drank after the shooting was contained in a report by Dr. Michael Baden. Baden stated in the 2002, document he understood the defense might introduce evidence Williams consumed “approximately 10 ounces of 80 proof Scotch” shortly after the shooting.