Shadow Unit: Elevator Speculations

For those of you who saw the latest episode, I have a weird one. In that bit where Chaz has that split-second of, “Uh, oh…” on the way down to the office, and then nothing happens (with that great line about salmon souffle–God, that was lovely), it seems to me he makes this really quick glance at the blank wall of the elevator. Was that a bloop, or my imagination, or a hint? In other words, is there something, uh, special about that elevator that we might or might not find out about later? Did anyone else even see it?