  It is shown that Collas and Klein (ArXiv : 0811.2471 [gr-qc]) wrongly
concluded that "negative frame dragging" phenomenon takes place at all finite
$r$ and $z$ coordinate values . We argue that a test particle with zero angular
momentum counter-rotates with respect to the source in the "time machine"
region only. In addition, Bonnor's spacetime has an event horizon at $r_{H}$ =
0.

General Relativity and Quantum Cosmology