In what circumstances will the admission into evidence of what has been called "coerced" or "involuntary" confession in a criminal trial result in the reversal of a judgment of conviction?

In People v. Cahill (1993) 5 Cal.4th 478, 20 Cal.Rptr.2d 582, 853 P.2d 1037, a majority of this court abrogated the well- and long-settled California rule that, in a criminal trial, the admission into evidence of what has variously been called a "coerced" or "involuntary" confession by the defendant requires automatic reversal of any ensuing judgment of conviction. In my dissenting opinion, I demonstrated that there was no reason to abandon or even reconsider that rule.