PvP - issue or cheat?

Just ran a match, where the other team's tank was literally jumping all over the place. One moment he would be within stun range, the next he would be on the other side of the arena, in the rafters, only to reappear next to me again after a second. I don't believe it would be the result of lag, because none of his team mates had the same issue, and no amount of lag would cause you to teleport from one side of the arena to the other, or cause you to appear in areas you cannot normally reach.

Has anyone else seen this happening?