I have a friend that does contract work for a Japanese company that has a US component. Even though we are not talking about the same company the problems my friend has told me about sound exactly like the ones the Tesla "insider" is talking about. This company has Japanese management and engineers that come to the US and aid their US division and it seems like a clash of cultures when they are trying to work out a problem. At least this company's Japanese employees can speak English, but their priorities are very different from the US employees therefore they focus on different problems. Like the Tesla Gigafactory, this company builds all of their equipment in Japan, disassembles it for shipment and reassembly in the US by the US team. When the "insider" talks about upper management not hearing about problems from lower management, imagine a US management team that doesn't want their failings known by the Japanese management team (and vice-versa). Nothing gets addressed.
I would hope Musk is smart enough to see what is going on and takes the lead on correcting this problem. Most bosses don't want to hear anything except everything is going great. Great bosses want all the information--not just the good stuff. That's what makes the difference in a well run organization vs. a poorly run organization. In a perfect world this "insider" should have no fear of going directly to the head person and relay what he sees and knows with no fear of reprisal. But, alas, we live in a far from perfect world. I wish Tesla luck with this management problem.