Playing Devil’s Advocate here.
If you had an alien ship with a propulsion system that was like nothing you’d ever seen, and you had no idea how it work, maybe a theoretical physicist, the most famous scientist in the world at the time, would be a person you would want to take a look at it.
Especially if your aerospace engineer had said he had no idea how it worked.
Perhaps. But Da Vinci drew models of humans with bat-like wings with which they could supposedly glide or fly. I give him credit for conceiving human flight, but it’s pretty clear that he was no aerodynamicist. And taking him the the crash site of an F-86 Sabre? He wouldn’t have a clue.