During the opening scene when Dr. Crusher is playing poker with Geordi, Worf, and Riker, Worf is shown with a card in front of him before they have been dealt. Dr. Crusher deals herself a 7 of clubs initially, but her up-card is shown as a ten of hearts. After the bet is made, her up-card changes back to the 7 of clubs.
In the beginning, you see the Exocomp turning off its tool automatically. However, when Data is testing the exocomp in the Jefferies tube to check if its is alive, the Exocomp is coming back without turning off its tool.
Data stated to Dr. Farallon that viruses are alive just as she is. Technically, viruses are not alive, even though they can be killed. Viruses are not made of cells, are incapable of homeostasis, and cannot reproduce on their own. They are particles, with a protein shell that contains either an DNA or an RNA genome.
Data states that he is considered "alive". Actually he is not. He is considered sentient and has human rights but he is not biologically alive.
When Data meets Geordi and Dr. Farallon in the transporter room in the first scene after the opening credits, he clearly smiles as he welcomes Dr. Farallon aboard. Data doesn't experience emotions, but has been practicing on the human act of smiling on several other occasions and it is safe to presume he has learned to use it correctly in situations like these by now.
Data claims that he is unique and unable to reproduce. He has apparently forgotten about his brother Lore (at large since Brothers (1990)) and Data's daughter Lal whom he sired in The Offspring (1990). However, these androids were constructed, and were not the product of an android reproducing.
The interior components of the exocomp include kit-bashed parts. The upper hull and bridge of a Klingon D7 warship are clearly seen.
The room in Engineering where Data tests the exocomp has a Jeffries tube that is waist high and appears to be at least 100 feet deep. In relation to the rest of the layout of Engineering, this would not have the Jeffries tube passing entirely through concealed structures but you cross eight feet of empty air to the right of the warp core.
When Data and Doctor Farallon are carrying the Exocomp across the lab to a different tube, a bug of some kind runs across the control panel in the lower-left part of the screen.
When La Forge and Picard are rescued and beamed back to the Enterprise, the transporter console can clearly be seen to wobble as they walk past it.