At the end of the day when the drone first becomes active, Seven notes that he needs to regenerate. Seven needs to regenerate on a daily basis. A number of scenes pass including the Captain saying that One has improved over the last several days. In the next scene, Seven has to instruct One on how to use the recharging chamber as though it is his first time, even though he needed to regenerate several days ago.
When the Borg sphere approaches Voyager, Seven of Nine and One enter the turbolift alone en route to the bridge. Arriving on the bridge in the next shot, Seven of Nine and One exit, with Janeway in front and two security guards behind.
Security Guard Shuffle: Three security guards baring phaser rifles (a black man, a white man, and a white woman) accompany Janeway to the cargo bay where she confronts One. They regroup in Astrometrics where the now weaponless white man and white woman guard the doorway (black man unseen, perhaps stationed in the corridor or perhaps joining Tuvok who's no longer in the grouping). Battle stations are called. Janeway, Seven and One exit. Janeway isn't seen in the corridor (possibly due to being out in front) but neither are any of the guards (apparently staying in Astrometrics in their role as window dressing - unless Astrometrics IS their battle station). In the turbolift, Seven and One have a personal conversation; even though the full turbolift isn't shown, they seem apparently alone. Arriving on the bridge, the turbolift doors open, but instead of Seven and One, closest to the doors, stepping out, Janeway steps out, followed by Seven, followed by One, followed by the black male security guard (armed), then the white male security guard (also armed).
The premise of the story is that some of Seven's nanoprobes, the Doctor's 29th century emitter, a Voyager science station, and a DNA sample from Ensign Mulcahey come together to create a 29th century Borg - One. The only biological matter in all this was from Mulcahey; so, one would think One should be a clone of Mulcahey, not a completely different person (with Mulcahey and One portrayed by different actors).
Spotting a maturation chamber near a fallen crewman, Seven says that the Borg assimilate and "do not reproduce in this fashion." She is not referring to growing drones in maturation chambers. She's referring to stealing mere tissue samples by which to grow drones.
Before the title sequence, in the shuttle pod, when they suffer the first 'bump' of 'turbulence', the camera pans a little too early on Paris in the pilot seat, while the camera shake that simulates the turbulence is still in progress. You recognize it because the stars in the side window behind Paris don't (appear to) move when the craft is 'shaking'.
When Janeway, Tuvok and a security team go to the cargo bay and wake up Seven because One has contacted the Borg, it is clear that one of the security team is chewing something.
The Doctor explains that his mobile emitter came from the 29th century, 400 years in the future. Since this show is set in the 24th century, the time difference is more like 500 years, as Torres has stated earlier.
As a Borg vessel approaches, Janeway and Seven share their full knowledge of the Borg with One in Astrometrics. One's fascination with the Borg is obvious. Janeway wants One's cooperation in fighting them off, but Chakotay's announcement of the Borg vessel's approach interrupts, calling all hands to battle stations. Janeway and Seven head to the bridge without One's answer. One follows them. On each side of the doorway stand two motionless security guards. They don't follow the Captain to protect her, they don't detain One from following her (even though he represents a potential danger to her and Voyager), and they don't go to their battle stations, which makes it entirely unclear who or what they are there to guard.
Seven's comment to One about the proper way to stand in a Borg alcove contradicts evidence seen in The Best of Both Worlds: Part 1 (1990)/The Best of Both Worlds: Part 2 (1990) where drones were seen facing both outward and inward in alcoves.