So, the first paper was about some teensy earthquakes up in Georgian Bay, Ontario. Now, you and I know what really caused them, but my poor buddies had to go out on a limb, and put in a possible cause, without knowing the first thing about rock mechanics (they are seismologists after all!).
They conjured up some hocus-pocus about hot rock viscosity differences at depth. Puleeze! So, these other guys skewered them.
It has been proposed (Dineva et al., 2007) that the location of upper to midcrustal earthquakes in the Canadian Precambrian shield is related to rheological differences between mafic dykes and country rock. We show that this hypothesis is critically dependent on assumed lithology, strain rate, and temperature, and consequently is not established with any level of confidence. Furthermore, it appears to lack self-consistency because it postulates earthquakes to occur in the ductile regime.
Now, these guys don't have any better solution, but decided to say something anyway. Good for them!
Of course, the original authors had to come back with some feeble defence, but that's boring. :)