Well, assuming everyone is following the law (and while Musk is eccentric... I don't see any reason to think that he's a criminal), we know what is going on inside of Tesla.
Everyone knows the dates when Tesla's bonds are due. We all know Tesla has lost $300 million / quarter per quarter for the last few years. Etc. etc. etc. Its all public information and there doesn't seem to be any "cooking of the books" going on right now.
In the case of Enron, it looked like a normal company but the executives were lying to the public. A few investors published articles noting that the numbers looked "off", which eventually prompted an investigation. Basically: if people lie, there's usually evidence in the numbers. Some numbers look wrong, certain things don't add up right, etc. etc. I've never heard of Tesla cooking the books.
