Quite unfortunately, one marauder decided to bail out and glitched himself into the ground. I'm not a quitter though, so I just went and did the second escalation encounter (since I hadn't done it yet) and hoped the zombies would despawn instead of just leaving the level (didn't know there was a marauder chilling underground). I found out that they didn't really feel like de spawning yet, which means I couldn't use fast travel to the end of the level because there was technically still a fight in progress. Neither could I naturally go back, since the door to the world spear bridge was closed. I wanted to end the level to see the progress and be proud of myself, so I went back to fight the zombies until they de spawned and suddenly, a marauder's dog appeared. That's when I figured out what went wrong and I started recording again. The rest is history. :)