If we look at Lee Bowers, James Worrell and William Whaley alone we have three people
Chances of dying in a motor vehicle accident in 1965 and 1966 combined: 50 out of every 100,000, which is 0.05%, or 1/20 of a percent, for one witness dying in a motor vehicle accident. 3 people who saw Oswald that day dying in traffic accidents. That amounts to 0.05^3 = 0,000125%. That's 1 in 800,000.
2-car smashup kills Oswald taxi driver: Dallas Man, 83, Also Dies in Crash on Trinity Viaduct
Dallas Morning News
December 19, 1965
By James Ewell
William H. Whaley, 60, the cab drive who picked up Lee Harvey Oswald just after President Kennedy was assassinated, was killed Saturday in a collision that also claimed one other life.
Whaley, of Lewisville, driving his cab, and John Henry Wells, 83 year old driver of the other car, were found dead in the wreckage after their cars crashed head-on at Hampton Road Viaduct shortly after 8 a.m.
A third victim, Navy Lt. Cmdr. Maurice R. Barnes, Jr., of Salt Lake City, Utah, a passenger in Whaley's cab, was injured and reported in critical condition late Saturday night at Parkland Hospital.
Sheriff's deputies said the car driven by Wells, of 3102 Toronto, apparently crossed over the center stripe. Whaley was driving south. The Wells car was heading north.
Whaley, who had more seniority than any man in the taxi system, was a Navy gunner during World War II, winning the Navy Cross for action off Iwo Jima.
The News broke the story of Oswald's getaway ride in the cab on Nov. 28, 1963. After becoming impatient with a city bus he had hopped near the assassination scene, Oswald ran to Whaley's cab at the Greyhound Bus Station and asked, "Can I take this cab?"
Whaley, commenting on the crowds milling near the Texas Schoolbook Depository Building, drew no conversation from Oswald, he said. Oswald sat tight-lipped until reached the address he'd given Whaley, a few blocks beyond the rooming house where the assassin had been staying in Oak Cliff.
The fare was 95 cents. Whaley later said, "If you can call a nickel a tip, I guess he tipped me."
A drizzling rain was falling when the cars collided Saturday. Lt.Cmdr. Barnes, 32, is a fighter pilot who had come to Dallas for a weekend of reserve training at Dallas Naval Air Station.
Whaley was also a Navy reservist, attached to the air wing staff at the Naval Air Station. Barnes is attached to naval Reserve Fighter Squadron 703 at the air station.
Sheriff's deputies said identification cards found on the injured man indicate that Barnes is an attorney. Deaths in the accident raised the Dallas toll of road deaths to 23 for the year, excluding traffic fatalities occurring within cities.
A motorist pulled into Fire Station No. 36 and Hampton and Denison to report the accident. Battalion Fire Chief J.R. McKim arrived at the scene to find one of his firemen , Wayne Wilkens, who had been en route to Station 36, already assisting Barnes.
McKim said it appeared that Whaley and Wells had been killed instantly.