What a strange coincidence - the only time I was separated from my wallet was also at MIA. My roommates had given me their rent money in cash just prior to me leaving for the airport. I was waiting for my connection and I had to make a call from a pay phone. I think I had a lot of hand baggage... anyway, I took out my calling card and placed my wallet on top of the pay phone. Made the call, put the card in my pocket and walked away with $800 in my wallet on top of the phone. I spent 20 minutes quaffing a beer at the bar and when went for my Visa to pay... uh-oh!
Ran faster than I ever ran before to the phone, about 400 feet away. The wallet was still there! (This was on Sept 22, 2001 so MIA was a ghost town).
I know this is not quite what happened to your husband but I know the terrible feeling in the pit of your stomach when you realize you've ****ed up.