A third vehicle driven by actor Luke Wilson was clipped by the Ferrari, Stoughton said. Wilson was not hurt.
The Ferrari's driver, who died at the scene, was a member of the family that Haas was staying with as he prepared to play this week in the Genesis Open at nearby Riviera Country Club, the golfer's manager Allen Hobbs said.
He was identified by coroner's officials as Mark William Gibello, 71, a resident of Pacific Palisades.
"While Bill escaped serious injuries and has been released from the hospital, he is understandably shaken up and — more importantly — his deepest condolences go out to the host family during this tragic and difficult time," Hobbs said in a statement.
The 35-year-old Haas will withdraw from the Genesis Open and return home to South Carolina to recuperate, he said.
Jay Haas, the golfer's father, told Golf Channel that his son has pain and swelling in one of his legs.
"Bill was very fortunate," he said.
Police were investigating whether speed was a factor in the crash. The driver of the BMW, a 50-year-old woman, was hospitalized in serious condition, Stoughton said.
A message seeking comment was left for a representative for Wilson, star of films including "Legally Blonde," ''Idiocracy" and "The Royal Tenenbaums."
Haas is a six-time winner on the PGA Tour whose most prominent victory was at the Tour Championship in 2011, which enabled him to win the FedEx Cup and the $10 million bonus. His most famous shot was in a playoff at the Tour Championship, when his ball was partially submerged in the lake.
He comes from a prominent golfing family. His father won nine times on the PGA Tour and 18 times on the PGA Tour Champions. His uncle, Jerry Haas, briefly played on the PGA Tour and is the golf coach at Wake Forest. And his great uncle, Bob Goalby, won the 1968 Masters.
Associated Press Golf Writer Doug Ferguson contributed to this report.