Many in the military tried to never get themselves into trouble, much less with their commanding officers. No one wanted to get in trouble.

You were one of them, but lately you'd been investigating behind the backs of your commanders, your teammates, and even MacTavish, even though he was your captain. It all started with one mission where the entire team nearly died under the rubble. Your attention was drawn to the patches of enemy soldiers that you took with you. It wasn't Makarov, why would he ever get involved with a PMC from another country? But then who would?

Shepherd and his personal PMC "Shadow Company". You had only circumstantial evidence of his guilt, which proved nothing, especially Shepherd actually coordinated Task Force 141. And if he found out about your investigation, you'd be in big trouble.

Now you're sitting in the archives, going through old files. You were doing this in MacTavish's absence because he didn't share your enthusiasm, and if he found out about the unauthorised investigation, you'd be in for a long talk.