Back to electrics of a sort.
But I don't think Tesla is going to make it.
Engineering is an applied science and has to take academics, dreamers, ideas and build something, which has been done.
The manufacturing aspect it seems is a disaster for Tesla.
Think of Tesla's manufacturing being a means to provide cheaper more efficient energy use solutions, and provide the electricity to run them. Some parts they sell like the cars, trucks, some Powerwalls and some Powerpacks. For others they retain ownership and sell the electricity like with some Powerwall, and Powerpack installations. Selling the energy is where the gravy train is. Not in the hardware that uses it. See cars, trucks, and oil.
I expect Tesla will succeed. When you have multiple people, corporations, and investment funds willing to invest hundreds of millions or even billions, you have to be doing something right. Tesla is changing the game, and providing cost savings to their customers in most markets they move into.
As for the accountant resigning. A company into as many countries and unusual financing like Tesla has, is a very different accounting beast than a normal company. Not only does Tesla have manufacturing, they also generate and sell electricity. They are a utility in many jurisdictions. That alone is an accounting nightmare. They also have projects where specific investors are invested in, but not invested in other projects. As Musk has said, Tesla is really an energy company, not just a car and battery manufacturer. When they sell trucks and charging stations to a company, they will also sell the electricity to run them. When they install a Powerwall or Powerpack system, they will sell the user the electricity to charge it, or if Tesla provided the capital to install it, then sell the electricity off of it to the customer. To top it off, they save their customers money in the process. Users of Powerwalls and Powerpacks have been very happy with them.
After the installation of a utility scale Powerpack system with wind farm to charge it in South Australia, utilities are looking at the savings South Australia is getting and want one for themselves. It reduced peaking power plant operation costs by 90%. Peaking power plants are considered a necessary evil by electrical utilities because they have to have them due to the large electricity generation power plants not being able to quickly ramp up and down electrical generation to stay with the fine grained changes in demand. Unfortunately the cost of the electricity generated by peaking power plants is very expensive compared to that generated by the large electricity generation power plants. A utility scale Powerpack system takes over the peaking function, and does it much better. Even if the energy used to charge it is generated by a regular power plant, it will still save the utility money. That is because even after losses during storage and conversion back into AC, the electricity will still cost much less than that generated by a traditional peaking plant.
I expect Tesla's biggest problem will be keeping up with demand. They will be a victim of their own success. I expect another giga factory or more being needed in the next decade, and they already have the investors begging to help pay for them, and pay for the Powerwall installations.