No. If 20 people indicate "Yes, I cheated on my taxes" that could mean that 10 of them misunderstood the question, 5 of them actually cheated, 3 of them were incorrect or were recorded incorrectly, and 2 of them actually did cheat. Of course, any of those numbers could be different. Now if you take these 20 people and extrapolate them to represent a population of millions, you are going to have a very bad time, as Richman had. If you had a far larger number of people instead of 20, say a number that was statistically relevant to your population size, then you should very well look farther into the issue with follow-up questions for those particular people to determine if they were entered in error or true responses.
Margin of Error Discussion:
Understanding the margin of error in election polls | Pew Research Center
People Lying on Polls:
Frequently asked questions | Pew Research Center
Do people lie to pollsters?
We know that not all survey questions are answered accurately, but it’s impossible to say that any given inaccurate answer necessarily involves lying. People may simply not remember their behavior accurately.
More people say they voted in a given election than voting records indicate actually cast ballots. In some instances, researchers have actually verified the voting records of people who were interviewed and found that some of them said they voted but did not. Voting is generally considered a socially desirable behavior, just like attending church or donating money to charity. Studies suggest these kinds of behaviors are overreported. Similarly, socially undesirable behaviors such as illegal drug use, certain kinds of sexual behavior or driving while intoxicated are underreported.
We take steps to minimize errors related to questions about socially desirable or undesirable activities. For example, questions about voter registration and voting usually acknowledge that not everyone takes part in elections. Pew Research Center’s voter registration question is worded this way:
“These days, many people are so busy they can’t find time to register to vote, or move around so often they don’t get a chance to re-register. Are you NOW registered to vote in your precinct or election district or haven’t you been able to register so far?”