Revealing mistake: When Kes is eating the spawn beetles, the same shot is used twice for when she scoops out beetles from the tray. The untouched beetles are all in the same place, and there is a beetle that is nearly flipped by her thumb both times.
Parturition - S2-E7
Revealing mistake: On the bridge, as Tuvok monitors and reports on the pursuing ship's weapons, you can see what looks like a wristwatch on his right wrist as he works the controls. (00:35:35)
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 ★