What is the test for suppressing evidence in a civil case?

"""A proceeding under . . . section 1538.5 to suppress evidence is one in which a full hearing is held on the issues before the superior court sitting as a finder of fact.' [Citation.]" [Citation.] . . . In such a proceeding the power to judge the credibility of the witnesses, resolve any conflicts in the testimony, weigh the evidence and draw factual inferences, is vested in the trial court. On appeal all presumptions favor the exercise of that power, and the trial court's findings on such matters, whether express or implied, must be upheld if they are supported by substantial evidence. The trial court also has the duty to decide whether, on the facts found, the search was unreasonable within the meaning of the Constitution. Although that issue is a question of law, the trial court's conclusion on the point should not lightly be challenged by appeal or by petition for extraordinary writ. Of course, if such review is nevertheless sought, it becomes the ultimate responsibility of the appellate court to measure the facts, as found by the trier, against the constitutional standard of reasonableness.' [Citation.]" (People v. Green (1996) 46 Cal.App.4th 367, 372.)