Is a respondent's failure to address an argument raised by the appellant at the hearing a concession or forfeiture?

A respondent's failure to address an argument raised by an appellant may, under some circumstances, be interpreted as a concession. (See People v. Bouzas (1991) 53 Cal.3d 467, 480, 279 Cal.Rptr. 847, 807 P.2d 1076, [stating that the People apparently concede a point made by the defendant to which they did not respond, either in briefing or in oral argument].) We do not, however, invariably interpret the failure to respond to an argument as a concession or a forfeiture. In People v. Hill (1992) 3 Cal.4th 959, 13 Cal.Rptr.2d 475, 839 P.2d 984, [w]e decline[d] to find a [forfeiture] based on nothing more than respondent's failure to respond to defendant's ... argument, which was itself raised for the first time on appeal. Such a rule would require a party to respond to his opponent's every argument, subargument, and allegation, no matter how meritless

[340 P.3d 317]