in games against ranked teams, with the exception of SDSU, BYU performed poorly. These losses plus losing two out of three at home against LMU doomed them. The WCC is a horrible softball league so thumping ne'er-do-wells doesn't count for much. Their RPI was poor at 52.
Yet they were playing well by the end of the season. Next season they lose a lot of seniors so they're likely to see a drop in performance.