When Wesley leaves to setup the probe for the modified neutrino beacon near the end of Act One, his position is taken over by another crewman as Worf picks up the transmission from Tomalak. At the start of Act Two when Picard has Worf hail the Romulans, there is a shot of Data AND Wesley sitting at their positions as Picard talks to Tomalak. Two scenes later, Wesley returns to the bridge to tell Picard the probe is ready to launch and then returns to his position.
When Geordi falls down the hole, his VISOR lands on his right-hand side above his arm. When he comes to, he finds his VISOR on the left-hand side.
During Picard's first conversation with Tomalak, the status indication lights at the aft end of the bridge indicate that the Enterprise is at Yellow Alert. However, during their second conversation, the status indicator shows the Enterprise at its standard alert status. Being less than half a light-year from Romulan space, and having a Romulan warship close-by would warrant the ship being at Yellow Alert, so they would not have stood down to standard alert status.
Geordi uses his phaser to make spikes while in the hole and it's still on his belt when the Romulan attacks him. When he wakes up it is missing but the Romulan doesn't have it. It is then missing through the rest of the episode until he returns to the Enterprise when it is back in his belt holster.
Geordi's tricorder disappears from his belt after he is knocked down by the Romulan and remains missing until he connects it to his visor. It is even missing in the scene where they discuss connecting the two devices.
Geordi makes the spikes to climb out of the chasm by melting metallic rocks in a crude finger-drawn channel, yet when he uses them to climb out, they are nicely rounded and finished.
The amount of sand that Geordi empties from his boot is far more than could reasonably have gotten inside of it.
The scene of the Enterprise & Romulan Warbird departing Galorndon Core is reused footage of Enterprise & Romulan Warbird Haakona departing Iconia in the Season 2 episode 'Contagion'.
How come the Romulans get to tool into the Neutral Zone anytime they jolly well please and without repercussions, such as what Tomalek does here, but then they'll attack the Federation whenever they do it, as shown in "The Defector"?
When the Romulan is knocked down by the rock-slide Geordi could easily have disarmed him. He had no reason to expect the Romulan to be friendly and just because he chose to help him doesn't mean he wouldn't also take his weapon when he had the chance.
Why couldn't the Enterprise separate and leave the saucer section there to get Geordi, and the hull section take the Romulan to his people? To avoid war and to save a life, wouldn't this make sense? If they didn't want to split the ship, maybe leave a shuttlecraft? They have transporters as seen later in the series.
When Geordi detects the neutrino stream from the modified probe, he automatically attributes it to Wesley Crusher. The Enterprise has whole teams of science and engineering officers, all of whom could and should have been capable of crafting such a device (especially Data, who is more intelligent than any of the crew). There is no reason for him to credit it to a teenage acting ensign.
Deanna speaks about how there is great hostility behind Tomalak's smile. But he is across the neutral zone, 6 hours away by warp from the ship. Too far away for her to insight anything using telepathy.