A friend of mine used to call me with technical/programming issues. He would explain the problem on the phone and suddenly come up with the solution, then thank

A friend of mine used to call me with technical/programming issues. He would explain the problem on the phone and suddenly come up with the solution, then thank me profusely even though I didn't really do anything. I don't know whether he was an ADHD case or not, but I thought he was, and he used to speak with a pronounced stutter especially when excited. Spending any time with him would make clear why: thoughts and ideas came at him so fast they were difficult to serialize through speech. Anyways, I'm not sure whether this is "body doubling" or "rubber ducking", or even if there isn't significant overlap between the two concepts.