Among the NTSB’s findings was that the car’s sensors weren’t designed to identify the side of the truck and, therefore, didn’t slow the car.
Four months after the May 2016 crash, which killed former Navy SEAL Joshua Brown, Tesla Chief Executive Officer Elon Musk held a call with reporters to discuss a new version of the Autopilot software. Enhancements to the radar used as part of the company’s driver-assistance system likely would have detected the semi trailer, he said at the time.
The "enhancements" refer to enhanced use of, not actually a hardware enhancement.
With systems like these you can't separate out "it's the driver's fault" (unless, perhaps, he was napping in the back seat) from "it's the system's fault." The two work together and no matter how much a driver is paying attention, there isn't time to react quickly enough from the moment you realize your HAL-9000 is about to drive you into a truck.