Other mistake: When Neelix and the Captain are following the unknown creature, it turns down a hallway and Neelix says it just ran into a dead end. The two follow and enter the transporter room on their right. However, when they exit the room, they turn to their right again, which should lead to a dead end. They needed to go to their left to go back to where they came from.
Continuity mistake: When Janeway and Neelix chase after the mysterious figure moving away from the down the dead end corridor, the wall is lit up, and the shadow moves across it showing direction of travel. After a quick cut, the wall they approach, and the corridor is noticeably darkened.