Doctor Who production is large-scale and gets noticed, even when the producers would prefer otherwise. There's no way for Gatiss or anyone else to be filming or even preparing to film the show without fans and/or the media finding out about it.
Of course people notice, which is specifically why you contrive for Gatiss to shoot a docudrama in the first place, so that one can more easily disguise work on the "secret" project as part of another project that's only tangentially related. Cool deal, because in addition to producing a nice docudrama, you also give yourself a perfect cover for filming flashbacks of the same period the docudrama covers.
At this point, with Moffat still (per the costume designer) working on the script, they're going to be rushing to start by the announced late March/early April date, not looking at secret filming before that. Unless we're to assume that he's finished the secret script, which is being worked on by the secret costume designer, and somehow filming alongside An Adventure in Space and Time without any of the people who are taking pictures of it noticing...
And costume designers never lie, do they? Also, why would the costume designer have to create any additional costumes? We're talking about simply using the actors from Gatiss' docudrama, in the costumes that have already been made for them.
I appreciate the desire to imagine ways in which there could be more than ~120 minutes of Doctor Who being made for the second half of 2013. It still baffles me that they couldn't pull together something more than that. But there's no sign of it happening
Ya mean other than the fact that the executive producer claims that the notion of a merely 60 minute anniversary episode is poppycock?
and given the time-scale on which the show is made, it's already too late.
Unless it's already well in the works. Heck, even if Moffat is still working on the final script, he may have had a general idea in mind since the very beginning, and has shot additional material throughout his time as show-runner, for possible inclusion in this anniversary arc. That said, there may be scenes/sequences of the anniversary story that have been in the can for years.
If they were making a second anniversary special to air before Christmas, they'd be doing it before Matt Smith's three-month break, not after.
Precisely. And exactly what I've been saying all along. I've repeatedly suggested that they'd shoot Smith whenever he's available, both before and after his break, and during the break, when he's not available, focus on sequences where Matt isn't needed.
Because there's no way a substantial portion of the anniversary is going to be done without the current Doctor.
Why not? There are plenty of scenes in virtually every episode which don't directly feature the Doctor himself. And if it's a multi-doctor story, or a story that plays heavily on his own history, and thus is flashback heavy, why would they need the current Doctor be available for scenes that focus primarily on his earlier incarnations? There were, after all, sequences in The Five Doctors that focused exclusively on longish sequences of the individual incarnations. I seem to recall a rather sizable portion of the story Involving Pertwee and Liz Sladden, which didn't involve Davidson at all, save as a disembodied voice over a walkie talkie. In fact, most of the scenes involved only one incarnation at a time, and the number of scenes where they directly interacted with the then current Doctor were few at best.