In the incident posted to YouTube, the car was driving autonomously when it illegally drove through the red light.

As Uber faces a potentially significant intellectual-property lawsuit filed by Google's Waymo, more details of the company's failed autonomous pilot program in California have surfaced.

The ride-hailing startup quickly pulled its prototypes out of California after one of the modified Volvo XC90 crossovers was caught on video driving through a red light. The incident coincided with a dispute with state regulators over permits required to test such vehicles.

Uber blamed "human error" for the red light violation, implying that a human was manually driving at the time, though LeftLane noted that the carefully worded statement left open the possibility that the Uber driver may have failed to intervene when the autonomous system failed to recognize the light.

"This is why we believe so much in making the roads safer by building self-driving Ubers," Uber spokeswoman Chelsea Kohler said last year.

The New York Times has uncovered documents claiming the autonomous system was active at the time. Mapping software deficiencies are said to be responsible for no less than six such incidents during the brief deployment in San Francisco.

"Our self-driving technology required human intervention," Kohler recently admitted to NYT. "The vehicle operator had time to intervene, but failed to take over before crossing the stop line and manually proceeded through the protected crosswalk."

The lawsuit is viewed as a significant setback for Uber as it attempts to bring an autonomous ride-hailing service to market. Waymo accused its former self-driving project lead, Anthony Levandowski, of stealing designs related to a proprietary LiDAR sensor system. Uber has vowed to fight the lawsuit.