As the question was whether you “knew”, not whether you thought you might have taken a risk, I wouldn’t suggest anyone answering “Never” was a hypocrite, although if the question had been whether people had ever driven with a quantity of alcohol in their bloodstream above zero, for anyone who was at all a frequent driver and a frequent drinker such an answer certainly would have been.
Over the years I have encountered one or two people who claimed to “never drink and drive” and indeed on occasions were critical of others who did so within the legal limit, and yet because of the general level of their evening consumption must often have been over the limit the following morning. The slow rate at which alcohol is metabolised by the body is still not appreciated as widely as it should be. Take a look at www.rupissed.com and work it out for yourself.
The proportion of non-drivers at 19% is very close to the proportion in the male adult population as a whole. I assume that, as past surveys have shown, the vast majority of readers of this blog are male. According to the DfT transport statistics, it is 20% of all males and 28% of all drivers. Interestingly, though, only 10% of males in the 40-69 age group do not have a licence, and so I would say amongst the blog’s core audience non-drivers are over-represented. Possibly some peopke make a choice early in life to be “drinkers” and not “drivers”, thus avoiding all the judgments and compromises that combining both in your life involves.