Why is the man who built Tesla's Model 3 returning to Apple?

I’d love to read the backstory.

From Daring Fireball’s John Gruber Friday:

Doug Field — who left Tesla in May after overseeing Model 3 production — has returned to Apple, working in Bob Mansfield’s project Titan group. Apple spokesperson Tom Neumayr confirmed with me only that Field has returned to Apple, but no one should find it surprising that he’s working on Titan.

From Road/Show’s Kyle Hyatt five weeks earlier:

Doug Field — who previously served head of Tesla Model 3 production until his April reassignment by CEO Elon Musk — opted to take a leave of absence in May in order to spend time with family and recover his energy. The word at the time was that he had not left the company, but now, according to a Tesla representative, that has changed.

This break occurs several months after Field was removed from his position as head of Model 3 production and replaced by Elon Musk. At the time, Musk stated in a tweet, “My job as CEO is to focus on what’s most critical, which is currently Model 3 production. Doug, who I regard as one of the world’s most talented engineering execs, is focused on vehicle engineering.”

My take: Doug Field — sounds like Musk’s loss, Mansfield’s gain.