Don't go too far away to look for those critters then. You can kill them without despawning the osd. Or you can just wait a couple of minutes if you're afraid it will despawn, after a few minutes the wave will end anyway.
They don't have a team big enough to test everything before release. They would need hundreds or even thousands of people for that. If you think it's so easy, why not apply for a job at Wildcard?