Yes, people have it all the time. Nothing to worry about. Good that you had additional evidence with you. I bet he anticipated you being caught by surprise, but you were well prepared. Most likely, he either cannot approve the case himself (not enough experience) or it's to do with country of origin (unfortunately, USCIS has elevated bar for certain applicants).
You'll probably hear from them in the next few weeks or month. If not, you can sue for decision after 120 days since the interview.
Congratulations, you're almost there!