Yes ...evaluation methods do vary ....

ref:
"First let us investigate the a-priori probability of "success" by
random chance given the current activity in the area at the time of the prediction. From August 23 through October 24 there were ...."

+ Why not use the entire record period for the background seismicity (20+ years worth?) not just "current activity...at the time of the prediction" (previous 2 months) for the first prediction evaluation above?

A gray area is assessing a "near miss" ...lots of ways there....