Continuity mistake: In the scene where Tuvok is performing the meld Seven of Nine's hair is noticeably out of place as a result of struggling in the restraints, yet just after the Vinculum is deactivated it is neatly back in place. (00:38:15 - 00:42:50)
Continuity mistake: When Seven and Naomi are playing Kadis-Kot, the pieces on the board and on the table change after Seven wins in the next shot.
Continuity mistake: When Tuvok and Paris go scouting the holodeck, Chaotica's fortress is visibly damaged, but in a later shot when Kim and Seven are looking at it from astrometrics, the building looks like it's completely intact.
Continuity mistake: Paris reports that several ships have dropped out of warp off of Voyager's port bow, but when the ships are put on screen, they are approaching from starboard aft.
Chosen answer: Before Q sent the Enterprise to the beta quadrant to officially contact the Borg, there were already indications that the Borg was beginning to reach Federation territory. There were remarks towards the end of the first season of the Next Generation that several of the furthest Federation outposts were being attacked by some unknown enemy. They suspected the Romulans, but when contact with the Romulans was re-established, they learned that it was not them. The Hansens had simply figured things out much earlier than anyone else in the Federation. They learned about the Borg nine years earlier, but Starfleet mainly took notice when their outposts started getting wiped out. It is logical to assume that there were indications of Borg scouting parties and research efforts well before that.
Garlonuss ★