When reviewing a judgment of dismissal after a demurrer is sustained without leave to amend, how does the court review the judgment de novo?

When reviewing a judgment of dismissal after a demurrer is sustained without leave to amend, "[w]e first review the complaint de novo to determine whether the complaint alleges facts sufficient to state a cause of action under any legal theory or to determine whether the trial court erroneously sustained the demurrer as a matter of law." (Aguilera v. Heiman (2009) 174 Cal.App.4th 590, 595.) Normally, we must next determine whether the trial court abused its discretion by sustaining the demurrer without leave to amend. (Ibid.) The appellant has the burden of demonstrating that the trial court erred. (Ibid.) In the instant case, the court granted plaintiff leave to amend but plaintiff failed to do so.