Visible crew/equipment: After the encounter with Borg in main engineering, when it cuts to the observation lounge with Guinan participating in the conference, at the start of the first shot you can see the shadow from the camera and crew person as it moves, at the bottom of the screen. (00:24:10)
Continuity mistake: In the beginning of the episode, Riker, Geordi, Worf, Data, and Pulaski are playing poker. Pulaski puts two neat stacks of chips in the center beside some chips in a pile. It then shows Worf putting similar stacks in the center but Pulaski's stacks are not visible and they should be. Then when Worf wins the hand, the camera is showing a wide shot of him pulling the chips towards him and you can see his and Pulaski's neat stacks of chips.
Continuity mistake: Klingons measure distance in kilometers in this episode. However, in all other Trek shows and movies, they measure in kellicams. [This was apparently during a misguided attempt by the Empire to adopt the decimal system (for Galactic consistency), even though the change was wildy unpopular with the public and military alike. While some ships, like in this episode, gave it a good try, the change was short-lived and eventually abandoned. However, until this claim can be backed up by a reference within Star Trek canon, it stands as a mistake.]
Continuity mistake: Looking at the shuttlecraft while sitting in the shuttle bay and after it has departed the Enterprise, you can tell they are different types of shuttles. The one in the shuttle bay has more angular lines with straight edges. The one outside the Enterprise has more curves than angles to its lines.
Other mistake: After the report that Picard is close to death, the scene shifts to a close up of La Forge's hand turning on controls. If you look closely, you can see that both panels are re-purposed CANX-23429 remote control units. The markings are for volume, radio, transmitter, receiver, phone jacks and a microphone jack.
Visible crew/equipment: Data tells Maddox that he formally refuses to undergo the procedure, but he supports Maddox's intriguing ongoing work. After Maddox comments that Data is remarkable, Louvois takes note that Maddox referred to Data as "he" instead of "it," and when Louvois walks toward Picard the blue tape mark is visible on the floor where she stands. (00:43:00)