For the cleaning bug, it's probably lag that allows them to get past it. The script is probably some kind of purge of everyone without the gang's tag on, but the base can only be purged once, otherwise it'd be unfair. If someone is lagging during the purge they probably wouldn't be registered and not be killed.

I guess they could make the script warp people out instead of killing them; you can't kill a lagging person (except with a melee), but you can warp them.