When trying to beam up Geordi and Ro at the beginning of the episode, Transporter Chief Brossmer's transporter console changes height between shots.
At the start, Chief Brossmer has an Ensign pip on her uniform. However, when Data interviews her about the transporter accident, she has a Chief pip.
When Riker and Picard leave the bridge and enter the lift to go to the memorial services, Ro and La Forge run into the lift after them and turn slightly so they won't bump into the doors as they close. Since they are still phased, they wouldn't have to do this, they could have just run through the doors. However, as they are only recently "phased", it's not unexpected that they would automatically do this.
Geordi La Forge and Ro Laren are accidentally cloaked and phased, meaning that they become invisible and their molecules pass through other matter (in other words, they are like ghosts). While it is questionable why, in this state, they are still able to touch certain items and don't pass through the floor, they obviously can still breathe and communicate with each other, given that they are in the same phase with each other. After all, there is no reason to assume that there isn't any phased air around them as well, which would make these things possible to them.
When the phased Ro Laren visits the bridge, she visibly touches the navigation console, which she should not be able to do.
When Ro steps off the turbolift on the bridge, the doors show Deck 10, instead of Deck 1.
In Ten Forward, Ro sets a Romulan disruptor to overload, then she and LaForge run off to take cover. As they do this, they pass a bunch of non-phased balloons that move from the air disturbance, something that should not happen while they are both phased.
When Captain Picard is on his way to Sick Bay he can be seen looking down at the phased Ro Laren. He shouldn't be able to see her so therefore he should be looking straight ahead instead of down at her as she is laying down.
When the phased Romulan gets off his chair and follows Geordi and Ro back to a Federation shuttle, he is literally a few feet behind them. They should have been able to see him if they had turned their heads even slightly at any point.
Near the end of the episode, Riker is playing the trombone in Ten Forward but his movements don't match the music that is heard.
When Brossmer reports to Data about the new chroniton fields on Deck 17, as he was following Ro and the Romulan, the doors are showing they are on Deck 8.
When Captain Picard and Commander Riker are walking into the ready room, where they are going to talk about the memorial service at 23:00 hours. You see Ro walk into the room from an impossible angle.
A commonly stated plot error is that La Forge and Ro are supposedly out of sync with the real world and cannot touch objects, yet they can still walk and move normally without falling through the floor. Star Trek writers and producers later explained this by stating that the ship's inertial dampers and gravity plating had somehow kept Ro and LaForge in vertical alignment with the ship, even in a phased state, yet horizontally they could still pass through bulkheads and solid objects.
Even though he is phased, Parem is able to not only sit in a chair on the Romulan ship, but it moves when he sits up to follow Geordi and Ro back to the Enterprise.
When Ro visits Picard in his Ready Room, she is initially almost just in front of the door. However, when she appears from the inside, she comes in though the side wall. Based on the position of the Ready Room door in relation to the bridge, it would seem that she decided to go through the bridge wall and then pass through the Ready Room wall and whatever lies in between, which was never shown.
Ensign Ro and Geordi have audible footsteps which should be impossible since they pass through objects.
Likewise, they should not have been able to see or hear anything.
Likewise, they should not have been able to see or hear anything.
When Ro is running through the ship to escape the Romulan, she runs in a straight line even though this is the least likely strategy to succeed. As evidenced by her attempt to attack the Romulan in the holodeck, neither phased being can see through walls, so Ro could have tried to attack again or simply have run in a different direction, and the Romulan would have had no way of knowing which way she went.
Picard says Ro lost her commission after the incident at Garon IV. It was actually Garon II, as explained in her introduction in Ensign Ro (1991).
When Chief Brossmer aborts the transport but Geordi and Ro don't rematerialize in the Romulan ship, Riker calls, "Chief?" before tapping on his communicator badge.