What is the test for a court to determine whether a plaintiff has been successful on a motion of appeal against a finding that the respondent has been found to have failed to exercise his discretion in weighing the relevant factors?

1315.) Courts will infer an implicit weighing well short of an express statement. (People v. Villatoro (2012) 54 Cal.4th 1152, 1168.) However, there must be something in the record to affirmatively show that the court did, in fact, weigh these factors. (People v. Cox (1991) 53 Cal.3d 618, 665 disapproved of on other grounds by People v. Doolin (2009) 45 Cal.4th 390.) "A failure to exercise discretion also may constitute an abuse of discretion." (People v. Sandoval (2007) 41 Cal.4th 825, 847-848.)