I've been in that situation on a map that size, the best tactic is to use a shotgun or other short/mid-range weapon and let the other team find you. They need the kill opportunities more than you do because they don't have nearly as many targets. It's not an advantage at all. He just so happened to think at a critical moment and did the best he could do. I've been on the other side of that situation and it's so much easier to win.