I don't think there is a right or wrong to this question.. the only right is the CAA inspector's interpretation of any single regulation.
Personally I don't log taxi time, but I had friends that used to do it as their 'intention was to take-off' (as written in the regulations). The fact they had to return back to the ramp for whatever reason (technical, weather) was irrelevant.
Ask 10 pilots.. get 20 different answers
