Continuity mistake: When Walter tells Peter that the Cocabeans he bought can't be eaten, he takes the roasting pan off the bunsen burner. In the next shot, the pan is still on the burner. (00:06:55)
Continuity mistake: After Fauxlivia shoots Joe and is dragging him to the bathroom to dispose of the body, she hears a knock on the door. During this shot, she is dragging him with his jacket over his head, which she is gripping. However in the immediate next shot, she is still dragging him by his jacket, only the jacket is much lower.
Other mistake: Peter and Dunham are alone in an apartment with blood coming in under the door. They are called and leave for the subway. Peter should have had to walk through blood to leave.
Answer: In the time line of Season 4, William Bell is trying to destroy both universes to create a new one, and he needs Olivia to power the collapse. So he helped her escape. But the real question is, if not in search of Peter, why Olivia has to travel to the alternate universe to be captured and replaced?
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