What Aaron Douglas said was that it was the last thing shot before the strike. The last episode filmed before that strike was "Sometimes a great notion", so the reveal is likely there (this was at least the plan before the series got a season 4.5 to finish the story, but from other recent comments, from Mark Stein, it looks like the final Cylon will be revealed quickly in S4.5).
While Starbuck is a very mysterious character since her miraculous return, and admittedly an almost perfect Cylon at first sight, certainly not everything we know indicates it's her. She's standing right there when D'Anna makes eye contact with Tigh and Tory, for one, but D'Anna is not interested in her (the whole "four in the fleet" thing). And she's also in the last supper picture; we know what RDM has said about that. Olmos also mentioned that they had, at an episode filmed well after the strike, gotten to understand a little about what had happened to Starbuck, and that it wasn't an "uplifting" understanding. If she had been revealed as final cylon already before the strike (in filming), then presumably they should have had a full understanding already.
What Tigh said is also not necessarily from the scene where the identity of the 5th is revealed; it could be taken from a later episode (there must have been some material fropm further in S4.5 available when that teaser was made). It could be that, say, D'Anna tells Tyrol and co who it is, without the 5th actually being present at the scene.