Fair, but establishing the truth from a mathematical standpoint and navigating in life, which involves a huge amount of (most often serviceable) rules of thumbs, are two different things. So there seems to be some arbitrary threshold where the rules of thumb is deemed good enough (eg. my toddler has chocolate all over him near the empty cookie jar) and when it's not (eg. put-up job). And from my experience, people will very, very often set that arbitrary threshold according to their own opinions.