Not that I doubt this story, but human memory is not very reliable. There's many studies that have been done on this. The fact that your wife would remember someone from three years ago who she met for 20 minutes is a little far fetched even if it was a significant meeting.
It also matters how you showed the picture. Depending on how you did it can influence people to remember incorrectly.
Koreans who grew up in Europe recognize Asian faces much worse than Koreans who grew up in Korea, and Koreans who grew up in Korea make mistakes in recognizing European faces.
It also matters how you showed the picture. Depending on how you did it can influence people to remember incorrectly.