Leaking information about the inefficiency of Tesla's production line could be construed as whistleblowing. Tesla is a public company and shareholders have right to know of issues that can have an impact on the viability of the company.
Tesla claims that some of the information is false (specifically the bit about punctured cells being installed). Whether this is true or not, the manner in which the disclosure occurred doesn't seem to be in the spirit of remedying the situation. It was to harm the company.
Whistleblowing is not about doing harm, it is about preventing it.
Say you dated someone at work and it didn't work out. Say you then went on a tirade around the office indicating exactly what their problems were (true or not), even to people who have no interest in dating that person. More accurately, you'd also pass off any and all benign details (because the installed software was indiscriminately passing off information). Would that be whistleblowing or would that be slander? Say that a good friend indicated that they were interested and you warned them away in private - completely different story.
Whistleblowing is ultimately harming the company and usually done by people trying to sabotage the company. Doesn't mean stuff leak isn't the truth. This guy leaked official documents to Business Insider that related to series 3 production and cost to produce batteries. Looking at the Tesla's accelerating cash burn(1.1 billion last quarter), he was being at least partially truthful that production costs are rising.
Whistleblowing is about protecting public interest: in some cases the public is investors, yes. Whistleblowing is not disclosing information carte blanche. That is espionage.
If Tesla were using punctured cells (still up in the air, given that the defendant admitted malice), that would be valid reason to leak. If Tesla are missing targets, that is a reason to leak.
However, if those two hypothetical facts form part of a larger corpus of trade secrets and other confidential information your intent is not to be a whistleblower. You are not whistleblowing. You are harming.
Yet another analogy to drive the point home. The most your HN profile has is your location. Clearly you are using a pseudonym. Let's say that maybe you run a darknet site trading in various nefarious activities. If I were to dox you, that association would surely be part of the corpus. However, would that be whistleblowing or doxxing? Would my intent be anything else other than malicious? Furthermore, maybe my research, keylogger or what-have-you might miss that detail: meaning that I failed to disclose the information that would cause public concern over those activities. I'm just sharing your secrets. Good, bad, it doesn't matter.
Whistleblowing is altruistic.
This guy wanted to do harm and the line is, in a rare occurrence, clear as the blue sky. If Tesla is found to be falling short according to the information he disclosed, they should answer for it. In the US they may not: fruit of the forbidden tree. This means that Tesla may get off the hook because of the carte blanche disclosure - would any good come from this? However, he should absolutely pay for violating the trust of his employer merely because he got passed up for a promotion. It is a negative sum situation. Whistleblowing is zero-sum (at least in today's world).
Whistleblowers are heroes. There is, by even the most microscopic margin, not a hero here. Don't sour the sacrifices of people who took risks for the humanity, for a single person seeking selfish vengeance.