That's absolutely not what happened. Board members are insiders and can't just sell their shares without making filings with the SEC about it. Since this didn't happen, we know that this "theory" is 100% wrong. Tesla is pulling back because all tech stocks are pulling back as treasury yields rise. There is an inverse relationship between the 10 year treasury yield and tech stocks.
This is strange. Ideally investors should not fall in to this trap. Bond yields are rising because the government is taking more and more loans to cover the rising federal debt. In absolute terms, the returns may be increasing. But the chances of default is going up and the purchasing power of US Dollar is declining. However, purchasing treasury bonds may be an attractive option in the short term, and I can't blame corporations for going for it.
The US technically can't default on the debt because the Fed will just print as much money as is required to redeem the bonds. So the risk of default is effectively zero. The consequence is the dollar becomes devalued, but that's not a default. Betrayal of the citizens, yes. Default, no.
All that aside, tech stocks will still trade inversely to treasury yields because that's just what they do.
They exist only because some people are unable to make decisions by themselves, and they want someone telling them what to do, even if that someone was wrong many times before. 
