>Actually, this restriction gave me my manager. It's probably incorrect too, since his definition of Median function was wrong.

Andrew is right, your manager is wrong. Even one point has a median, though not highly useful. Certainly 2 points have a useful median, and it's equal to the mean.

That's spoken statistically. Practically speaking, there may be some reason why a small number of points is not a sufficient number for computing for some reason...there is, for example, a problem with variance and degrees of freedom in estimation when there are very few data points.