In a little hurry?

I was paying attention to what was in front of me as I took a glace in the side mirror I saw a car moving from the left lane to behind me and thought "ok" a car is behind me now and then went to pay attention to what is up ahead. (all of this was like 2-4 seconds) Suddenly engine rev noises. I saw the same car that was behind me punching it and passing me in the emergency lane.