Lee Semel's answer in particular would make a great post here: a "to don't" list. You may wish to go through and identify the cognitive bias or biases each is an example of.
It obviously depends on whether the expected utility of both people having the correct answer exceeds the disutility of spending the time and energy (physical and emotional) to locate/confirm it.
On Quora: What are some stupid things smart people do? Examples of common types of stupidity that are typical of otherwise very smart people.
Lee Semel's answer in particular would make a great post here: a "to don't" list. You may wish to go through and identify the cognitive bias or biases each is an example of.