Day 4: 12:00 P.M.-1:00 P.M. - S4-E6
Continuity mistake: Day Four: 12:00 PM - 1:00 PM. When Tariq and Behrooz are shown in split-screen digging Debbie's grave right after the commercial break (12:54:10 by the show's clock), Tariq's white t-shirt is covered in dirt. When the shot goes back to them a minute or so later, Tariq's t-shirt is much cleaner.
Day 4: 12:00 P.M.-1:00 P.M. - S4-E6
Revealing mistake: During the rescue, a few shots after SecDef Heller announces to Jack that he's also out of ammo, you see a shot of the bullet-riddled car taking a few more bullets. The new bullet holes obviously fade in.
Chosen answer: Nobody knew, not even the writers, until at least halfway through the season when they were writing the end. They wanted to keep all options open.
Nick N.