Any one ever hear what Fiona does for a living when she's not helping Michael? I know Sam is retired, I assume from the Navy where was once a SEAL. WHich is how he met Michael and all his FBI contacts. But Fiona has all the time any time to help Michael. Just wondered.
In "Sins of Omission" Fiona is jeolous of Samantha's relationship with Mike before he met Fiona. It makes no sense what ever, it was 10 years ago. After all we know she still has a big thing for him even if he doesn't share the feelings right now she keeps coming back. Not only that but if you remember her boy friend who drives the Ambulance? Even he knew Fiona was still in love with Mike. So when you love some one today what they did before you met them is totally unimportant.
In "Signals and Codes" Michael is solving a case & trying to get back into the Agency which ever one that is, and Fiona will stick by him put her life on the line for him if need be and he doesn't even bother to thank her most of the time. What a shmuck, but then she's in love and he's willing to use her for his own purposes without regard for her needs wants and desires much at all. Yea he's a shmuck.