Autopilot has been in the crosshairs of federal crash investigators, dating back to a 2016 crash of Tesla Model S in Autopilot mode that killed its driver after the car failed to stop for a tractor trailer that cut across its path.
More recently, investigators with the National Transportation Safety Board were called into to review details of a March crash that saw a Tesla Model X slam into a highway divider in Mountain View, Calif. The driver died.
Tesla has said the driver ignored the car's warnings to take back control of the car, while his family is considering suing on the grounds that Tesla ignored the driver's previously raised concerns about Autopilot acting up on that same stretch of Silicon Valley highway.
NTSB and National Highway Traffic Safety Administration officials also are investigating a recent Tesla Model S crash in Florida in which two teens died and one was injured.
The car hit a concrete barrier at high speed in a residential neighborhood and burst into flames. Autopilot is not thought to be a factor, but investigators are looking into the ensuing battery fire.
Just prior to Utah police announcing that Autopilot had been in use according to the car's driver, Tesla CEO Elon Musk posted a series of tweets that played up the safety of his car.
"What's actually amazing about this accident is that a Model S hit a fire truck at 60mph and the driver only broke an ankle," Musk tweeted (although initially reported as an ankle injury, South Jordan officials said the injury was a broken foot). "An impact at that speed usually results in severe injury or death."
Musk also lamented media coverage that he said glossed over the 40,000 annual U.S. road deaths, and acknowledged that while no technology is perfect "a system that, on balance, saves lives & reduces injuries should be released."