"She is starting to damage my calm."
I really don't remember getting medals much, but recently I was startled to hear the announcer yell out "SHOWSTOPPER!!" I had just blown up two guys with the rocket launcher on Reflection by Jetpacking up over a balcony.
I had to go to my stats to look up what a Showstopper was. Turns out one guy was getting assassinated by the other. When I killed them both I got the medal.