At one point, the Doctor states that he has the cortical inhibitor on Seven set to maximum but it is no longer working. Later he can be seen adjusting the device to attempt to help Seven.
When the reflections of the little girl and the Klingon are seen at the same time that Seven can be seen, the movements of the reflections are not in sync with Seven's movements.
When Seven is restrained on the bio-bed and has to be sedated, Jeri Ryan's double ear piercings can be seen when she turns her head.
While strapped to the bio-bed and yelling about all the noises she hears, a filling can be seen in the upper left side of Jeri Ryan's teeth. The EHM would have fixed that for her.
When Seven leaves Engineering after attacking BElanna, Chakotay says she is on deck 9 section 32. However when Janeway calls later to inform Tuvok that Seven has been contained she states that Seven is on deck 10 section 32. Seven would not have enough time to get to the next deck by the time she was contained therefore it is a mistake.
When reviewing the log of one of Seven's errant personalities, the log states the stardate as 52356.2. While this stardate would be correct for the episode's current date, Seven states that the person in question was assimilated thirteen years ago. Since the personalities act as if they are perceiving events right before they were assimilated with no knowledge of events after that, the personal log should have given a stardate consistent with thirteen years ago, not the present.