Whoa that's terrible!!! I'm so glad that your fiance found that!!!! Props to him!
Something (NOT as severe, of course) that happened to me once when I was in school was an orange rolled underneath the pedals of the school bus I was on, and we got stuck going up a hill. We had to wait there to be "rescued" by another school bus. I guess that the driver couldn't change gears or something, and I don't think that she knew it was an orange until after we were rescued. It was really weird... but I had never thought about the same thing happening on a plane!!! You should be so proud of him!!! (I'm sure you are) I always watch those "seconds form disaster" plane crash stories, and they are always saying that it is a chain of events that go wrong... How awesome that your fiance broke the chain!!!