Plot hole: While Ensign Ballard is trying to dazzle Torres, she switches between English and Kobali. Torres gives her a look and when questioned, she tells her, "You were speaking Kobali." Others in Engineering are also directing strange looks toward Ensign Ballard. The problem is that the Universal Translator should be taking care of this, causing the others to only hear what is being said in their preferred language.
Character mistake: When the now human Borg children are sculpting, one of the children tell Seven he made a cube that's precisely 1/1,000 the size of a Borg vessel. Borg Cubes are described as 3 kilometers in length, if not bigger. 1/1,000 of that would be more than 9.8 feet in length. 1/10,000 the size would have been a more accurate description.