Orthogonal columns imply orthogonal rows?

Question

The original question is: Column Vectors orthogonal implies Row Vectors also orthogonal?

A counterexample with zero entries is given in one post. However, my question is whether pairwise orthogonal columns with no zero entries imply pairwise orthogonal rows?

Answer 1

The answer is no. Here's a counterexample: $$ \pmatrix{1&2\\-1&2} $$