G.R. No. 229450 - Philippine Savings Bank vs. Sakata

On December 17, 2002, Maria Cecilia Sakata opened Savings Account No. 035-111-05773-6 at PS Bank Dasmariñas, Cavite Branch.
On December 20, 2002, she opened Current Account No. 035-101-00399-5 and received checks Nos. 99501–99550.
The Specimen Signature Card bore her full signature “Maria Cecilia E. Sakata” and instructions to transfer between accounts.

Sakata worked in Osaka, Japan from May 4, 2003 to July 27, 2006, remitting funds and issuing checks for family support and mortgage amortization.
She returned to the Philippines on July 27, 2006.

On August 7, 2006, in closing her checking account, Sakata noted “lumped” entries in her passbook from May 2003 to September 2005.
She requested itemized transactions for October 2004 to September 2005; PS Bank refused.
Upon update, her savings balance dropped from ₱1,000,000.00 to ₱391.00; a deposit of ₱4,488,197.01 and withdrawal of ₱4,751,112.42 on September 16, 2005 were recorded.
PS Bank provided copies of statements and two original checks in April 2007; Sakata discovered 25 checks bearing forged signatures (Check Nos. 159654–159698) totaling ₱1,087,500.00.
PS Bank refused to release originals; Sakata formally demanded production of the 25 checks, specimen signature cards, and re-credit of ₱1,087,500.00 with interest in March 2008.

Sakata filed Civil Case No. 2283-08 claiming sum of money and damages; PS Bank counterclaimed asserting validity of checks and alleged authorization of Sakata’s mother to receive new checkbooks.
On June 27, 2013, the Regional Trial Court ruled in favor of Sakata: PS Bank to pay ₱1,087,500.00 plus ₱20,000.00 attorney’s fees.
PS Bank’s motion for reconsideration was denied; it appealed to the Court of Appeals.
On August 25, 2016, the Court of Appeals affirmed the trial court decision (deleted moral/exemplary damages), awarding:

Principal ₱1,087,500.00 with 12% interest (Sep 8, 2008–Jun 30, 2013) and 6% thereafter.
Attorney’s fees of 10% of total obligation and costs.

PS Bank’s motion for reconsideration before the CA was denied on January 16, 2017.
PS Bank filed a Petition for Review on Certiorari under Rule 45 before the Supreme Court, raising mixed questions of fact and law, challenging findings of forgery, applicability of Section 23 and Section 14 of the Negotiable Instruments Law, and asserting shared‐responsibility doctrine.

Whether the Court of Appeals erred in finding that the 25 withdrawn checks were forged and thus inoperative under Section 23 of the Negotiable Instruments Law.
Whether respondent Sakata was negligent—triggering the doctrine of shared responsibility—and must shoulder part of the loss.