Thank you for sharing your experience!
I was always told by lawyers not to give long stories at the interview. I was never asked such question by adjudicator. Any open ended long answers can lead to more questioning and searching for inconsistencies to accuse one of fraud.
I was asked questions such as "How did you meet"? And my answer was short: "We met through a common friend". That seemed enough. A smiling and friendly adjudicator can be a mask they wear. Generally, adjudicator is not a friend.
I think, in your case, you had a nice person new to USCIS, that's why they need others to review their work before decision can be made.
Keep us posted!