The Wormhole wrote:
Having Smith direct a Doctor-lite episode would defeat the purpose of that since he can't very well direct an episode at the same time he's supposed to be off filming another one.
I wondered about that. If what Whistleblower says is true, which it very possibly is not, then I suspect the Doctor-lite episode won't be double-banked, it will simply be in a separate production block of its own. Instead of a 36-week shoot for series 8, they may have a 38-week shoot to accommodate Smith's directorial debut.
To be honest, I wouldn't be surprised if Smith wrote the episode as well.