I thought of my story! And it should make you feel a tiny bit better (not as good as your self inflicted happy ending though).
At least the restaurant you went to actually existed.
When I was 18, I invited a girl to a beach party being thrown by all of the cool kids at school (of which I was not one). The party was at a beach on Lake Michigan in Chicago. I packed a cooler and picked her up in a western suburb. We got stuck in horrible traffic and it took almost 2 hours to get there. (First date in traffic also sucks). When we finally arrived... no party. Not sure if it ended, I was at the wrong beach, or they were just punking me.
If I were older I could have played it off and done something else in Chicago but I had no money and we were dressed for the beach. We awkwardly hung out there for a while then I drove her home.
No second date.
hahahaha you could have brought your backseat lawyer friend along to help you out
I'm sure he would have said something BRILLIANT!
Perhaps something witty like, "maybe they all left because they saw you coming".
That would have endeared her to nee for sure.