The California Highway Patrol on Friday pulled over a Tesla Model S that was traveling down the road—but whose driver appeared to be asleep at the wheel. The vehicle was traveling southbound on Highway 101 in Palo Alto.

Officers said that they were unable to get the man's attention.

"One of the officers basically ended up going in front of the vehicle and basically tried to slow it down," a California Highway Patrol spokesman told KCBS radio. The process took about seven minutes, and the car traveled for about seven miles before coming to a stop.

The driver was Alexander Samek, who serves on the Los Altos Planning Commission. He was arrested for driving under the influence.

So how was the vehicle able to travel for more than seven minutes with an apparently sleeping driver? The obvious theory is that the Model S had its Autopilot system turned on, but officials said on Friday that they hadn't confirmed that yet. It's quite possible that Autopilot saved Samek's life.

The situation is a bit of a puzzle because Autopilot is supposed to detect if a driver's hands are on the wheel and disengage if they're not. Tesla has steadily tightened up these rules, with recent revisions of the software warning drivers in as little as 30 seconds. So if the driver did fall asleep at the wheel the car should have started slowing down on its own within a few minutes.

In a similar case back in January, police encountered a man asleep behind the wheel of a Tesla car on the San Francisco–Oakland Bay Bridge. When police woke him up, he insisted that everything was fine because his vehicle was "on autopilot." Unfortunately for him, there's no autopilot exception to drunk-driving laws.