There looks to have been nothing contentious about the case: there appear to have been, for example, no motions filed by the respondent at all, which tends to suggest the family made no effort in court to stall or otherwise impede the judicial foreclosure process.
As far as I can see, Kavanaugh’s mother heard only one motion in the matter: a motion to dismiss brought by the plaintiff, which doesn’t seem to have been prejudicial to the interests of the family.
Hardly a case to foment a seething desire for revenge to be unleashed some decades later. We’ll likely need to look elsewhere for motive.