Corrected entry: Jack is on the phone with his wife and daughter, while CTU listens and tries to trace the call. When Eli enters the room where the women are being held, Jack tells CTU to mute the line so Eli can't hear them. When Eli finds the phone, he asks "who is this?". Jack responds with a threat that scares Eli into hanging up the phone. If the phone was muted, Eli shouldn't have been able to hear Jack.
24 (2001)
61 corrected entries
Visible crew/equipment: When Nina's just been shot, and makes it to the barn to call CTU (around 7.10am), while she's speaking on the phone there's a cameraman visible on the right hand side (DVD). (00:12:40)
Day 6: 6:00 AM - 7:00 AM - S6-E1
Jack Bauer: Do you understand the difference between dying for something and dying for nothing? The only reason I fought so hard to stay alive in China was because I didn't want to die for nothing. Today, I can die for something.
Question: Was Nina recruited as a spy before she joined CTU or after? Also, as she wasn't working just for the Drazens, what was her primary mission?
Answer: According to Jack in season 5, Nina was "deep cover" before the pair ever met, so it's safe to assume she was recruited before she joined CTU. As for what her primary mission was, who knows? Perhaps it was to gather sensitive intel and pass it on to her superiors. Given that she worked for an intelligence agency, it's not a stretch. Or perhaps we may find out in season seven.
Correction: As we find out later, Nina is in fact Yelena and is working for them, so she might not have muted the phone for the sole purpose of Eli finding it.