Perhaps slightly off-topic, but at least tangentially related: When we play Feud with the math students at the Governor's Honors Program each summer, we aim for the top 5-7 answers for each question. This occasionally means that some of the answers we use are indeed wrong. (An example: One year. for "Name any computer programming language," several of the students answered, "DOS.") However, the survey answers we use are given by the math students themselves, in a poll that we take on the first night of the program approximately three weeks ahead of the contest. As a result, we don't feel obligated to weed out incorrect answers.
We have had similar issues when playing games such as Pyramid and Go with the kids. It's rare, but occasionally the person (people) giving the clue will say something incorrect, but somehow the receiver will discern the right answer. Admittedly, we've varied in how we've dealt with this; for example, in Go, we did alter the rules to state that the word in play must be a reasonably correct answer to the clue question. (It's also why I'm SOOO glad we don't use Go as one of the games any more.)