SAN DIEGO — This much is not in dispute: Inspectors could not duplicate the sudden, unintended acceleration that a motorist reported last week when his Toyota Prius reached 94 mph on a California freeway. They tried during a two-hour test drive.

Disagreements begin over what that means. John Gomez, an attorney for the motorist, James Sikes, says it is insignificant and not surprising.

"They have never been able to replicate an incident of sudden acceleration. Mr. Sikes never had a problem in the three years he owned this vehicle," he said Sunday.

But Kurt Bardella, a spokesman for U.S. Rep. Darrell Issa, R-Calif., said the failure to duplicate the stuck accelerator, along with a vehicle design to prevent such occurrences, raises questions about the driver's story.

"We're not saying Mr. Sikes is wrong or that he lied, we're saying that questions have arisen in the investigation," Bardella said.

Toyota planned to announce preliminary findings of its investigation at a news conference today in San Diego.

The National Highway Traffic Safety Administration is looking into claims from more than 60 Toyota owners that their vehicles continue to accelerate unexpectedly despite having their vehicles repaired.

Technicians with the NHTSA and Toyota could not duplicate what Sikes said he experienced, according to a congressional staffer's memo prepared for the House Committee on Oversight and Government Reform. "Every time the technician placed the gas pedal to the floor and the brake pedal to the floor the engine shut off and the car immediately started to slow down," the memo read.

According to the memo, a Toyota official who was at the two-day inspection last week in suburban San Diego explained that an electric motor would "completely seize" if a system to shut off the gas when the brake is pressed fails, and there was no evidence to support that happened.

"In this case, knowing that we are able to push the car around the shop, it does not appear to be feasibly possible, both electronically and mechanically that his gas pedal was stuck to the floor and he was slamming on the brake at the same time," according to the memo.

Toyota has recalled millions of cars because of floor mats that can snag gas pedals or accelerators that can sometimes stick. Sikes' car was covered by the floor mat recall but not the one for sticky accelerators. He later told reporters that he tried to pull on the gas pedal during his harrowing ride, but it didn't "move at all."