Elon Musk is digging in his heels in defending Tesla's autopilot feature on its Model S cars. In emails with Fortune Monday, Musk reportedly told a journalist the death of the driver who was using autopilot was not of material importance to Tesla shareholders, and therefore didn't need to be disclosed sooner.

The feature is coming under scrutiny after a driver who had activated autopilot on the highway died in a crash in Florida in May. The journalist, decorated financial writer Carol Loomis, was asking the company why it had not disclosed the death to shareholders before a public offering of more than $2 billion in shares, which occurred roughly 10 days after the May 7 crash. Tesla put out a public statement about the crash just last week.

The delay in informing shareholders compounds concerns about the safety of Tesla Model S vehicles and the transparency of Tesla as a company. Even before the crash, some were alarmed by videos posted online of drivers allowing autopilot--sort of a teaser of anticipated full self-driving car technology--to take over the wheel of the car.

Witnesses of the Florida crash have reported the Tesla driver who died was watching a film from the Harry Potter series at the time of the accident, a detail that would seem to further bolster perceptions that drivers are placing excessive trust in an untested feature.  

Musk told Fortune that the crash "is not material to the value of Tesla" as far as shareholders are concerned.

He was then quoted as saying, "Indeed, if anyone bothered to do the math (obviously, you did not) they would realize that of the over 1M auto deaths per year worldwide, approximately half a million people would have been saved if the Tesla autopilot was universally available. Please, take 5 mins and do the bloody math before you write an article that misleads the public."

The comments echo a statement published last week to the website for Tesla. "This is the first known fatality in just over 130 million miles where Autopilot was activated. Among all vehicles in the US, there is a fatality every 94 million miles," the statement reads.

It continues, "As more real-world miles accumulate and the software logic accounts for increasingly rare events, the probability of injury will keep decreasing. Autopilot is getting better all the time, but it is not perfect and still requires the driver to remain alert."

Inc. has reached out to Tesla for comment and will update if the company responds.

Published on: Jul 5, 2016