Oh right, I wondered about that mission, like some sort of prank by the designers. I did beat it few times by being in that box and sniping them from it, not sure what's the catch, sometimes they do manage to hit you when you're standing there, but not most of the time. Maybe you have to be at some very exact coordinates in there.
Although the last time I played it, I found another spot where you can easily survive, if you go back past the building you came from to the ferris wheel area and to the left, you can hide inside the building there, normally this is an area where the enemies also spawn if you're not there. Then you should only have some of them left when the helicopter arrives.
Oh, the memories, many hours went into Call of Duty multiplayer back in those years, I spent the most in COD:MW2 and COD2. COD:MW2 was when they started locking tweakability, no dedicated servers etc. although one thing I liked about matchmaking, there was some variety, I often found servers people setup boring as they'd be running the same map(s) and gametype over and over. Though that's not specific to Call of Duty.
COD Black Ops released 1 year later by another developer retained the developer console, but I stopped following franchise afterwards. I've read the recent release broke the sales record for the franchise. Multiplayer of the new MW2 is supposed to be really fun, but one guy on YouTube said regarding the singleplayer campaign that they just didn't have the balls to be bold. Heh, I still remember there was some controversy over No Russian mission in the old MW2. Man, when did all those years go, the old MW2 runs even on Windows bloody XP...well maybe not the original anymore due to Steam, although it seems there was always someone who coded some mod for it lifting the original copy's limitations, no DRM is more like a side effect, but yeah, console and moddability. I guess debate over ethics regarding such mods are a debate for another topic.
COD World at War is an interesting one from the era, WWII again, but I think it is good at showing the misery of war. It has the gritty atmosphere and a fitting soundtrack. Also the first entry with zombies. Do they dare to remaster this one properly? But I'm also curious how COD1 and COD:UO would look if remastered. The first ones, no regenerating health and if I recall correctly, no medpacks on Veteran difficulty, but a good 'ol quick save/quick load feature.