A disgruntled former Waymo van operator who worked for a contractor of the self-driving-vehicle company was arrested on charges of intentionally causing one to crash on January 30.

According to Car and Driver and the Arizona Central, Raymond Tang was caught on video intentionally swerving in and out of a lane occupied by a Waymo test van, and then eventually slammed on his brakes in front of it, causing a collision. At the time, he was allegedly harassing two of the self-driving-capable vans. The Waymo vehicle that was eventually involved in the collision was being driven by a human, not by the company’s autonomous system.

The newspaper reports that during an interview with police, Tang admitted to “brake-checking the Waymo,” in other words pulling in front of the vehicle and then slamming on his brakes.