That is incredible. In an audience of over 2000 people, attending a show largely featuring piano performance, there must have been a few professional musicians, and an international relations student gets chosen and just crushes it. That's the next La La Land story right there.
Coincidentally, I just had my own more modest sight reading experience last night. My daughter is singing Phantom of the Opera in her voice class, so a few weeks ago I picked up one of the songs in hopes that she'd sign as I accompany her. We did that yesterday after dinner, and then she asked if we could go through all of the rest of the songs in the book. The ones I had not even looked at before, let alone played. Gulp. It was a bit of a mess, but we got through it, and she had a tremendous time, it really just melted my heart and this was why I wanted to pick up piano in the first place.
I just had to tell the story to my new piano teacher today, and she pulled out a few sight reading exercises and we spent the first part of the lesson on that. Awesome, I'm definitely going to make that a part of my practice routine.
Also, back when the movie came out, I tried picking up a La La Land solo medley and failed utterly as I could not begin to get the more complicated jumps and runs, at all. One of the things I'd love to do is to get back to it and be able to tackle it someday.