2000 Bar: Is XY justified in signing the certification? Why? (5%)

2000 Bar: As counsel for A, B, C and D, Atty. XY prepared a complaint for recovery of possession of a parcel of land against Z. Before filing a complaint, XY discovered that his clients were not able to sign the certification of non-forum shopping. To avoid further delays in the filing of the complaint, XY signed the certification and immediately filed the complaint in court. Is XY justified in signing the certification? Why? (5%)
No, Atty. XY is not justified in signing the non-forum shopping certification because the Rule requires the plaintiff or the principal party himself to sign the certificate (Sec. 5, Rule 7) since the rule requires personal knowledge by the party executing the certification, unless counsel gives good reason why he is not able to secure his client‘s signatures and shows that his clients will be deprived of substantial justice or unless he is authorized to sing it by his clients through a special power of attorney (Escorpizo v. University of Baguio).