Balanced Binary Tree
That Wikipedia article is using a different definition of "balanced":


  A balanced binary tree has the minimum possible height.


Therefore, since a perfect binary tree of height $d$ has $2^{d}-1$ nodes, if a tree has $n$ nodes, the minimum possible height for that tree is $\left \lceil \log_2n \right \rceil$, and the tree you mention does indeed satisfy that condition.

Observe that the usual definition of "balanced tree" is in an asymptotic setting, i.e. depth is $\mathcal{O}(\log n)$.