Around 1 a.m. on March 6, a driverless car from the tech startup Cruise was trying to make a left turn when it encountered something its algorithms probably couldn’t predict: An Infiniti Q50 performing ‘donuts,’ a popular and unlawful pastime for some of the city’s night owls, in the middle of the intersection.

The two vehicles collided head-on, according to a report that the company later sent to state authorities. Cruise said its vehicle suffered moderate damage, but that no one was injured.

The experimental car had no driver at the time -- an increasingly common sight in San Francisco -- as part of an ongoing test of late-night robotaxis.

Whether the Infiniti driver suffered any damage or injuries isn’t clear. They didn’t stick around.

It was the latest example of a pattern bedeviling tech companies that are trying to make driverless cars a reality: hit-and-run crashes seemingly caused by human drivers....