Was that on the beach fort map? Only joined in the last moments but I noticed some people way of course there. I placed deathzones all over that map, but it seems there is a small gap of less then 2 meters between the fort outer wall and area trigger of the deathzone. There is no way someone accidentally takes this path, someone must have spend time to map the exact edge of the deathzones in order to cheat his way around the map.
Anyway I changed the map so the deathzone is bigger now and harder to bypass, I don't have time to retest the map though, it is not unlikely that I made some other changes long time ago that I never tested afterwards. But I could send Shadowman this updated version (if he is still running the TR2 server, been so long since I was actively playing this game) so next time people try to take this shortcut they will die screaming.