Given petitioner’s failure to submit any objective proof that he had mailed his answer, it was neither arbitrary and capricious nor contrary to law for DHCR to find him in default (see Matter of Szaro v New York State Div. of Hous. & Community Renewal, 13 AD3d 93 [2004]). Nonetheless, in view of petitioner’s advanced age and Housing Court’s appointment of a guardian ad litem for him in the related holdover proceeding, the matter should be reopened at the administrative level for the reception of additional evidence bearing on whether good cause exists to excuse petitioner’s failure either to timely answer or to retain proof of the alleged timely mailing of his answer (see Matter of Dworman v New York State Div. of Hous. & Community Renewal, 94 NY2d 359, 373 [1999]). We note that DHCR does not object to reopening the matter for this purpose. Concur — Mazzarelli, J.P, Friedman, Nardélli, Buckley and Freedman, JJ. [See 2007 NY Slip Op 31864(H).]