Something similar happened to me. I was at a restaurant, it was a small chinese place, and their cards reader froze and didn't work. I didn't had cash on me as this was my lunch break and I knew they always take cards.
I was amazed how much the waitress was prepared. I told her that I don't have cash and she told me I can to pay with immediate bank transfer.
She took out a phone and made a invoice with QR code. I scanned the code from my bank app and in a few seconds it was done... Just like LN 😀