How have courts dealt with the issue of a defendant's failure to object to his sentence on appeal?

evidence presented at trial that defendant damaged the vehicle. Defendant forfeited this issue when he failed to object to the requested restitution at the sentencing hearing. (People v. Smith (2001) 24 Cal.4th 849, 852 [sentencing error is forfeited by failure to object unless it involves a pure question of law that is correctable without referring to factual findings in the record or remanding for further findings].)

In any event, he has failed to meet his burden on appeal. Once the victim makes a prima facie showing of economic losses incurred as a result of the defendant's criminal acts, that showing "establishes the amount of restitution the victim is entitled to receive," and the burden shifts to the defendant to disprove the amount of losses claimed by the victim. (People v. Fulton (2003) 109 Cal.App.4th 876, 886.)