Tesla Inc. is no longer cooperating with the U.S. National Transportation Safety Board investigation into the crash of a Model X in autonomous mode that killed a man in Mountain View last month — but just why remains uncleaer.

Depending on whom you believe, either Tesla quit the investigation, or it was thrown off it.

Of the two possible options, the latter is the more controversial. The NTSB said in a press release that it had revoked Tesla as a party to the investigation due to Tesla “releasing investigative information before it was vetted and confirmed by the NTSB.” More specifically, the NTSB is upset that Tesla not only spoke to the media while the investigation is still underway but also blamed the driver for the accident, which involved the Model X running straight into a set concrete road barrier.

“It is unfortunate that Tesla, by its actions, did not abide by the party agreement,” NTSB Chairman Robert Sumwalt said. “We decided to revoke Tesla’s party status and informed Mr. Musk in a phone call last evening and via letter today. While we understand the demand for information that parties face during an NTSB investigation, uncoordinated releases of incomplete information do not further transportation safety or serve the public interest.”

Tesla denied the claim, saying it “willingly withdrew” from the investigation and charging in a statement that the NTSB is more concerned with press headlines than actually promoting safety.

“Last week, in a conversation with the NTSB, we were told that if we made additional statements before their 12-24 month investigative process is complete, we would no longer be a party to the investigation agreement,” a Tesla spokesperson said. “On Tuesday, we chose to withdraw from the agreement and issued a statement to correct misleading claims that had been made about Autopilot — claims which made it seem as though Autopilot creates safety problems when the opposite is true.”

Whichever version is true, Tesla’s falling out with the NTSB is not a good thing for the company going forward. What is beyond dispute is that the Model X, in autonomous mode on March 23, slammed into a fixed concrete barrier on Highway 101 in Mountain View, the heart of Silicon Valley, killing Walter Huang.

Unlike previous incidents of autonomous vehicles killing people — such as the first Tesla death involving a Model X and a tractor-trailer and the Uber pedestrian death in Arizona — this accident involved an inanimate object that the technology arguably should have avoided.

Investors weren’t happy with the news, as Tesla’s share price dropped $6.68 today, or 2.28 percent, to close at $249.08.

Photo: Tesla