Nice story. Sometimes there are some of these design flaws that somehow escape unnoticed while design phase or reliability testing phase. I remember some of nokia phones bursted or produced lot of interference when in gas stations or phone kept on charging and at the same time talking on the call.
I love the fact that you say that your idea was "just good enough to work." I think that's one area that all engineers can never get enough experience, which is "Determining when good is good enough!" Quite a trial by fire for a new engineer!
This is a fantastic story George! It is always surprising to hear about some of the oversights that happen out there, especially in the medical industry. You'd think there would be some kind of additional level of scrutiny, but I guess theres not. It isn't going into space after all.