For the second time in recent days, Tesla and one of its customers are at odds over a collision. Earlier this week, a Utah-based Tesla owner claimed that his parked Model S decided to crash into parked trailer of its own accord, something Tesla disputes. And now there's Arianna Simpson, who says that the safety features in her Model S did nothing to prevent her crashing into the back of another vehicle at speed. However, like the prior case, Tesla says the vehicle's data logs don't support the story.

On April 26, Simpson was driving north from Los Angeles on I-5, cruising in autopilot mode. "All of a sudden the car ahead of me came to a halt. There was a decent amount of space so I figured that the car was going to brake as it is supposed to and didn't brake immediately. When it became apparent that the car was not slowing down at all, I slammed on the brakes but was probably still going 40 when I collided with the other car," she told Ars.

In contrast, Tesla says that the vehicle logs show that its adaptive cruise control system is not to blame. Data points to Simpson hitting the brake pedal and deactivating autopilot and traffic aware cruise control, returning the car to manual control instantly. (This has been industry-wide practice for cruise control systems for many years.) Simpson's use of the brake also apparently disengaged the automatic emergency braking system, something that's been standard across Tesla's range since it rolled out firmware version 6.2 last year.

In a statement to Ars, the company said:

"Safety is the top priority at Tesla, and we engineer and build our cars with this foremost in mind. We also ask our customers to exercise safe behavior when using our vehicles. Since the release of Autopilot, we’ve continuously educated customers on the use of the feature, reminding them that they’re responsible for remaining alert and present when using Autopilot and must be prepared to take control at all times. Tesla Autopilot is designed to provide a hands-on experience to give drivers more confidence behind the wheel, increase their safety on the road, and make highway driving more enjoyable. Autopilot is by far the most advanced such system on the road, but it does not turn a Tesla into an autonomous vehicle and does not allow the driver to abdicate responsibility."

Simpson describes herself as always having been "super pro-Tesla and self-driving things in general," but she's not happy about the nature of her interactions with the company since. She believes Tesla lacks empathy and is being "pretty awful throughout the process."

Thankfully, there were no life-threatening injuries resulting from this crash, which provides a cautionary tale when it comes to the state of self-driving vehicles in 2016. As Tesla was keen to point out to Ars, its cars issue numerous warnings and notifications about the limits of the various driver assists and safety systems. But among the public—and its customer base—there are still misconceptions over what those limits are as well as possible confusion as to who exactly (the car or the driver) is in charge.

We should expect to hear many more cases of drivers blaming their own cars for collisions in the coming years, according to Andrew Rose, CEO of compare.com. "People will claim autonomous mode was responsible for accidents and at first the insurance companies will deny claims, telling them 'yeah sure, of course the car was driving itself...'" he told Ars. That may be a relatively simple determination to make given that kind of information is captured within vehicle logs, as both this and the Utah case have demonstrated.

For now, simply keep in mind that the days of completely autonomous vehicles capable of taking us from A to B with no intervention other than telling it the destination are still at least two decades away. If behind the wheel before then, you—not your car, not the company that built it—are in charge of where it goes. That also means you're liable for anything it hits. Be safe out there, people.