He earned a degree in it, and seems to know what he's talking about.
What evidence do you have of that?
The word “probably” indicates uncertainty.
Therefore, there is no evidence, just suspicion he is not doing the actual engineering work himself.
OK, what reason do you have to suspect he is not doing the actual engineering work?
He has a BS in physics.
And decades of experience building up engineering firms from almost nothing. Perhaps I'm in a different environment than you, but I know more than one top-tier engineer that didn't even graduate high school let alone get a 4 year degree in physics.
If someone has a computer science degree but never writes code are they a software engineer?
Why are you under the presumption that he did no domain specific engineering at Tesla and SpaceX? And let's not go in circles and repeat your previous arguments please.