Yeah, but you see, this is just you showing that you haven't understood the explanation in your link. It says,
"Similarly, if a particular group of people is measured to have a lower average IQ than the general population, it is an error to conclude that a randomly selected member of the group is more likely to have a lower IQ than the average general population. Mathematically, this comes from the fact that a distribution can have a positive mean but a negative median. This property is linked to the skewness of the distribution."
A property with a numeric scale, like a distribution, can have skewness; a binary (yes/no) distribution cannot. Skewness occurs when a few people have very extreme values of the variable, throwing the median off from the mean. This can't happen when the only possible values are 0 and 1. The average value of the variable must in fact be the probability that any actual member has a 1 as the value.
Incidentally, this is a classic illustration of why, in my opinion, it is dangerous and typically futile to memorize lists of fallacies. More likely than not, you'll pull one out inappropriately because you never understood why it was a fallacy to begin with. Learn to reason *correctly,* not incorrectly, and then you'll detect the fallacies for yourself, because they won't be good reasoning.