From the Herald article:
"The Tesla driver told
police he thought the other driver, who was behind the wheel of a Toyota Tacoma, tried to run him off the road.“They had some disagreement,” Mills said. “The suspect followed him to the next set of lights.”
The truck driver, who Mills said stands over 6 feet tall and weighs more than 250 pounds, approached the Tesla on foot, “yelling,” and lashed out when the car “lurched at him.” The Tesla driver blamed his nerves and lack of familiarity with the new car.
It was then, Mills said, the suspect “smashed the window with his hand.”
So, seems he was a new owner.
At least there were no guns involved.