How do I tell whether my child prefers a team role or is being pushed into it?

At the robotics display, my eleven-year-old pointed to the mechanism he had built. I asked why someone else was doing the presentation.

He said, "Because I wanted to make that bit work."

I keep encouraging him to volunteer as team leader. He keeps choosing assembly and testing. Last week another child spoke over him while he explained a fault, which made me worry that he wasn't getting a real choice. But the club mentor says members choose roles together, and my son says he doesn't want me asking for a leadership turn on his behalf.

I paid for the club hoping it would give him confidence. He comes home excited about gears. I may be measuring confidence by whether he stands at the front. What would you ask to distinguish an unwanted role from a preferred one, without treating enjoyment of the building work as a problem to fix?