That doesn’t really answer the question. “Not a good fit” is a bit of a euphemism in the industry - it typically is a polite way of saying “I didn’t get along with the CEO/CTO/leadership because X, Y, and Z” - and that’s what GP (and myself) are looking for. I doubt we’ll get an answer anytime soon - he’s a classy guy and probably still under NDA with Tesla.

With the benefit of hindsight, I'm really happy both that I joined Tesla and also that I left it. I have no regrets at all.

I learned a lot while I was there, but Elon and I had different opinions about some things. It was clear that he wasn't going to bend or change, and those points were important to me.

I have some principles that are extremely important to me, and if they aren't aligning, then it is best to acknowledge that and do something about it, than deny it and be frustrated or unhappy.

E is a force of nature -- for better and worse :-). I'm glad we have someone like him in the world, but that doesn't mean I want to be directly involved.

Any lessons on sticking to principles and how to make sure they align going into a project/role? I imagine it's hard to so preemptively rather than when push comes to shove.

It doesn’t really matter - he’s no longer there and I’m sure much happier because of it. There are a lot of irrational things management can come up with. Sometimes the manager in particular is a sociopath or narcissist. Or maybe you unknowingly offended them in some way. At that point there’s no reason to stay, regardless of the reason.