To put a bit more nuance on this: in the US, verbal contracts are hard to enforce because they're usually hard to prove. But a verbal contract you can prove is

To put a bit more nuance on this: in the US, verbal contracts are hard to enforce because they're usually hard to prove. But a verbal contract you can prove is enforceable just like a written contract (with some important exceptions covered by a state's statute of frauds). Even in the case of conflicting stories, a jury can believe one side's testimony over the other. Elon's problem here is that "I left thinking we could get a deal done if we did some other stuff that could get a deal done" is not a statement about an agreement. The Saudis don't have to honor his private prediction.