This question contains spoilers for David Mitchell's Slade House.
The first four chapters of Slade House end with the narrator in the twins' attic, sitting around a candle with them. I noticed that during Sally's viewpoint, they've switched places around the candle:
Nathan
Lady Grayer on my left, but she's younger now, younger than Mum. To my right is Jonah Grayer but he's older than the Jonah in the garden.
Gordon
On my left there's Chloe, in a hooded padded robe thing. On my right there's... a male Chloe.
Sally
To my right sits Kate Childs, the Wicked Witch of the West, dressed in a gray Arab-style cloak thing, but now in her midthirties. Have I really been here so long? Have all those years been stolen from me? To my left hovers another vaguely familiar face... Jesus, it's Melbourne Mike.
Freya
Left of the candle hovers a woman in her midthirties. She's familiar... it's Maggs the landlady, but twenty year younger, slimmer, blonder, smoother-skinned and eerily beautiful. Right of the candle is a man of the same age, also blond, and also known to me... as I study him, a young Fred Pink emerges from his face.
This seems like a mistake to me, but is there any evidence whether or not it really is (from inside or outside the book)? Has this been changed in another edition, has Mitchell commented on it, etc? As far as I can tell from the story, while the twins can work all sorts of magic, switching places in the attic should be impossible, since time doesn't pass in the attic between these scenes.