Are you sure? I've never played a single multiplayer game where a single match lasted less than... I believe 4 minutes, but 99% were always at least 5 minutes long. then again, I've never played Counter-Strike. Are the matches similar to missions from, say, Perfect Dark? In there, the single-player missions are incredibly small, and although average play length for most missions is at least 15 minutes, you can complete most of them in very little time, and a few in times close to a single minute. Perhaps a screenshot including the mission timer at the end of a match might clear thigns up for me, but does the timers I've seen count up, (time elapsed) or down? (time remaining)
Wake up, George Lucas... The Matrix has you...