Just by him asking if it's a FN shows he know something about firearms. It's not as common of a firearm like Glock. Seems like most people see a "plastic" gun they think Glock. Glad everything worked out ok for you.
I had a fun experience at In-n-Out. Lots of stares and double takes. But what really got me. I overheard someone jokingly said "someone call 911". But I think my "Don't neglect the balls" shirt may have lightened the mood.