Tesla has denied that its cars suffer from suspension defects, suggesting that comments from the US National Highway Traffic Safety Administration (NHTSA) have been misinterpreted. Yesterday, a spokesperson for the agency said it was "examining the potential suspension issue on the Tesla Model S," with NHTSA administrator Mark Rosekind later adding that the agency was in "data collection mode."

Tesla says it's given the NHTSA all the data it needs

Tesla notes that this is not a formal investigation, and that the company supplied the NHTSA with all the relevant data back in April. "NHTSA has since told us that we have cooperated fully and that no further information is needed," said the automaker. However, the NHTSA's interest is not just in the safety of the Model S, but in claims that Tesla asked one customer with a faulty vehicle to sign a non-disclosure agreement as part of a deal to fix their car at a discount.

This particular case is what seems to have sparked the NHTSA's most recent comments. In a story published on Daily Kanban, Edward Niedermeyer covered a thread on the Tesla Motors Club forum, in which a poster described the suspension on his 2013 Model S failing at a low speed. The car was out of warranty, but Tesla offered to repair the damage at half price — paying 50 percent of the $3,100 bill.

The NHTSA calls the NDA "troublesome"

The car's owner said he was asked to sign a "Goodwill Agreement" in exchange for the discount, which includes a clause stating that the signee will "agree to keep confidential our provision of the Goodwill, the terms of this agreement and the incidents or claims leading or related to our provision of the Goodwill." The NHTSA described this as "troublesome" on Thursday, and had "immediately informed Tesla that any language implying that consumers should not contact the agency regarding safety concerns is unacceptable" and that it "expects Tesla to eliminate any such language."

Tesla described the idea that it would prevent a customer talking to the NHTSA "or any other government agency" as "preposterous." It says that such Goodwill Agreements are only used to "ensure that Tesla doesn’t do a good deed, only to have that used against us in court." Still, the agreement clearly states that the owner has to keep the incident "confidential" — and it’s a little troubling that the company would make any effort to prevent a customer from talking about a problem with their car.

Tesla tacitly admits there may be some fault with the agreement, stating that it "will take a look at this situation [and] work with NHTSA to see if we can handle it differently." It adds that the contract does not mention "NHTSA or the government," and that the company has "absolutely no desire" to stop customers from reporting faults.

surprisingly personal attacks

The blog post continues by criticizing Niedermeyer — the Daily Kanban writer who first covered the issue — in a surprisingly personal attack. It describes him as "the same gentle soul who previously wrote a blog titled Tesla Death Watch," and even suggests that Niedermeyer may "have something financial to gain by negatively affecting Tesla’s stock price."

Tesla may certainly be worrying about the shorting of its stock (CEO Elon Musk warned investors about this earlier this month), but it's surprising to see a large corporation personally attack a journalist in this fashion. It's the sort of thin-skinned behavior we've seen before from companies like Theranos.

As for the suspension fault which led to the original article from the Daily Kanban, Tesla claims this was a "very unusual use case." The Model S in question had over 70,000 miles on the clock, and the owner "lives down such a long dirt road that it required two tow trucks to retrieve the truck." Any further news on a potential defect will have to wait for the NHTSA — if it ever starts a formal investigation.