Visible crew/equipment: During the last scene in the infirmary, Bashir has a word with O'Brien about Garak's condition. Then, just as O'Brien walks towards Garak, on the console's reflective surface, we can see the reflection of the moving boom mic (beside the ceiling's black stripe pattern) at the bottom of the screen. (00:42:50)
Visible crew/equipment: After Garak takes out the first Cardassian while hiding in the broken stasis chamber, when it cuts to Nog walking towards O'Brien, there are three tape marks visible on the floor behind O'Brien. (00:25:25)
Answer: Part of the answer is found in "The Search: Part II" (season 3 episode 2). The female changeling told Odo that "the urge to return home was implanted in your genetic makeup. So he hardly has a choice in that. But being a sentient, thinking being, he recognizes the atrocities that his people are behind and he can't condone their actions. So it's a matter of his conscious mind warring with his instinctual gestalt. But on a more general level, we all instinctually wish to be among people who are like us. No matter how much he may like and love those around him and feel that emotion returned, there are numerous aspects of his life and existence that absolutely nobody on DS9 can empathize with or understand. And that's not even to address the pure joy and acceptance that is brought by the Great Link.
Garlonuss ★