I have to say I was much more impressed with last night's episode than the previous ones. An amazingly good story, and quite emotional in places. A few niggly plot issues, and there's still a lack of distinct characterization of the three companions, but a much better overall plot.
It's an interesting point. Yes, that was a significant historical inaccuracy. I can see why they probably chose to have no smoking (social responsibility and all that, plus, would all the actors even have agreed to being exposed to smoke?), but it was inaccurate.
Presumably, this would be the parallel universe in which the Earth has been invaded by cybermen several times, highly intelligent silurians and sea devils occupied Earth before man came along, Australia was ruled by a ruthless dictator, and the entire centre of London got evacuated 40 or so years ago because of dinosaurs roaming around (just 10 years after the underground was disrupted by yeti). Maybe there isn't much smoking in that parallel universe
(has anyone ever smoked on Dr Who?)