There's a lot of cheaters in Gambit at the moment. It could be that. I saw somebody invade recently and run around the map at about 5X normal speed to kill everyone. This wasn't lag or latency the guy went in and out of buildings searching for people like the Flash it was the craziest thing I ever saw. There are no combinations of armor or perks that let you run that fast, I know I've been playing a long time.