Tesla Inc will probably have to go to trial to fight claims that a sudden acceleration defect in a Model S caused a fiery crash in Indiana that killed the driver and a passenger in 2016.

A California state judge said in a tentative ruling he was unconvinced that a review of the car’s data recorder shows the crash was all the driver’s fault.

The wreck in downtown Indianapolis killed the driver, lawyer Casey Speckman, 27, and her boss, Kevin McCarthy, the CEO of a software company.

Speckman’s family claims the Model S, which was owned by McCarthy, sped up on its own - exhibiting what is called “uncommanded acceleration” - as Speckman was trying to evade a car driving the wrong way on a one-way street. According to the family, the car continued to speed up even though Speckman had let up on the accelerator pedal moments before the crash.

Tesla maintains there was nothing wrong with the car. It says the data event recorder shows that the woman kept her foot on the accelerator pedal before the crash and never attempted to brake. It also says police reports reveal that Speckman was found to be driving with a blood-alcohol level more than twice the legal limit.

In his tentative ruling Feb 1, Santa Clara County Superior Court Judge Frederick S. Chung concluded that Tesla had failed to show that the family didn’t have - or at least could not come up with - evidence to refute the company’s version of events.

He pointed to the findings of an expert hired by the family to examine the car’s event data recorder. The expert’s report, the judge said, “raises a triable issue as to whether the subject vehicle’s EDR was functioning properly and as to whether the subject vehicle was properly responding to all driver inputs at the time of the crash.”

McCarthy’s family is also suing Tesla over the accident. It claims that flaws in company’s battery technology and the design of its doors caused the car to burst into flames after it hit a tree, making it impossible for McCarthy to get out of the burning car.

Tesla and its lawyer didn’t immediately respond to a request for comment after regular business hours.

 - Bloomberg