Consider the classes Admin and HColumnDescriptor.
HColumnDescriptor is really referring to a "column family" and not a "column" (i.e., family:qualifer).
Likewise, in Admin there is a method called "addColumn" that takes an HColumnDescriptor instance.
I labeled this a bug in the sense that it produces conceptual confusion because there is a big difference between a column and column-family in HBase and these terms should be used consistently. The code works, though.