Comment on "Hole digging in ensembles of tunneling molecular magnets"
  Tupitsyn et al. [Phys. Rev. B v69, 132406 (2004)] have recently reported results for the relaxation of crystalline systems of single--molecule magnets, such as Fe_8. They claim that, quite generally, (1) the magnetization and hole widths of field--distributions evolve with time t as sqrt{t}, and (2) the holes' line shapes are Lorentzian. We give a counter--example to these conclusions, and show that the main assumption on which they rest is invalid. 
J.J.Alonso (1), J.F.Fernandez (2), ((1) Universidad de Malaga, Spain,   (2) CSIC and Universidad de Zaragoza, Spain)