Yeah, I don't think the producers should be responsible for Chris's stupidity.
While we are on the topics of production errors, I honestly think the Room of Harmonic Convergence in "The Golden Cup of Belshazzar" was a production error rather than a dead end. IIRC, you can hear a faint "door chime" at one point in the run. And that would be too brutal if it was an actual deadend.