  Shegelski, Kavka, and Hynbida have developed a method for calculating the
lifetime of a particle initially localized in a potential well exactly quantum
mechanically by employing a heuristic expression for the lifetime <t>. Their
method allows for the inclusion of a bound state, and their results for
tunneling through a centrifugal barrier demonstrate the major role that bound
states play in determining the lifetime. In this comment, I show that one can
greatly simplify the analysis by calculating <t^2>^(1/2) instead. Results
obtained are exact when no bound state is present. In the presence of a bound
state the results are only approximate but still illustrate the influence that
the presence of a bound state has on the lifetime.
