Revealing mistake: When Tom is reading the Klingon romance novel, he presses the button to turn the page, yet the text is always the same.
Revealing mistake: When Paris and Rayne are driving through the Los Angeles suburbs in her van, they never change their direction of travel, but they pass the same sequence of houses twice. (00:31:05)
Revealing mistake: In the basement, when the camera is in a close up on B'elana's face, the edge of the prosthetic at the left side of her hairline is visible.
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 ★