Chris Lattner, in an interview with Joe Rossignol at MacRumors:
This was a very difficult decision, because I care deeply about the technology and people at Apple and because I could see myself staying there for many more years. In the end though, the opportunity to dive into a completely new area and work with the amazing Tesla Autopilot team was irresistible.
I believe him, but I still can’t help but wonder what the hell is happening with Project Titan.