I just watched that clip and two things came to mind;
One, clearly he was smoking in the sunroom ,but it appears that the camera man was outside,in that the windows were shown in every shot?
Two, if a plumber comes to your house and you happen to be smoking in your own home,is this now his place of work,and would you then be in violation of his rights?
I say this because the house has become the candidates home for the duration.so perhaps they are entitled to smoke and the cameraman is likened to the plumber?
Its an interesting one..Maybe TV3 could clear it up..