Gately, the wraith, and the figurants — "The seated shadow of somebody in…"
The seated shadow of somebody in a hat is still there out there in the hall, though if the whole interlude was a dream it isn’t and has never been there, Gately realizes, squinting a little to try to make sure the shadow is the shadow of a hat and not a fire-extinguisher box on the hall wall or something.
Context
Dream-status with legal stakes: if the wraith-night is a dream, the A.D.A.'s hat-shadow in the hall is dreamt too "and has never been there." The tense-scramble ("is still there… isn't and has never been") does the work — Gately's whole criminal jeopardy hangs on which frame the shadow belongs to.