Based on past catalogs, I compute that Dennis' prediction has a 30.5% chance of coming true by chance. In addition, his zone is within the Hector Mines aftershock zone and there is a an 86.5% chance of an aftershock of magnitude 3.5 or greater in the next four days based on the Jones-Reasonberg formula. Combining these two probabilities gives a total chance of 90.8%

I'll follow up at the end of the window to see if any events happened in Dennis' times, space, and magnitude windows.