Palace: Baste Duterte seems ‘unconcerned’ about VP Sara’s GenCorp stake

Davao City Mayor Sebastian “Baste” Duterte testifies as a hostile witness on the 31st day of Vice President Sara Duterte’s impeachment trial at the Senate in Pasay City on Tuesday, Sept. 29, 2026.

The STAR / Ryan Baldemor

MANILA, Philippines — Malacañang said Davao City Mayor Sebastian “Baste” Duterte seems "unconcerned" about Vice President Sara Duterte’s financial interest in GenCorp Industries Inc. following his appearance as a witness in his sister’s impeachment trial.

At a press briefing on Wednesday, September 30, Palace Press Officer Claire Castro declined to make a conclusion as to whether Baste was covering for Duterte after claiming in his testimony that he only learned about GenCorp through the trial.

“Hindi natin masasabi. Hindi natin mabibigyan ng anumang paghuhusga ang kanyang statement. Ang ipinakita lang niya kahapon ay wala siyang alam. Wala siyang alam. Hindi niya inalam at parang wala siyang pakialam,” Castro said.

(We can’t say. We can’t give any judgment on his statement. What he showed yesterday was that he knows nothing. He is clueless. He did not bother to find out and he seems unconcerned.)

Baste appeared in the Senate impeachment court on Tuesday, September 29, to testify on the alleged unexplained wealth of the vice president, particularly on what the prosecutors claim as a conflict of interest involving GenCorp’s contracts with the Davao City government.

He was later declared by the Senate impeachment court as a hostile witness.

The prosecutors’ arguments stemmed from the P34.2 million worth of 15 contracts in Davao City awarded to GenCorp from 2022 to 2026. Baste, on the other hand, claimed there were 19 contracts.

The vice president is listed as a stockholder in GenCorp, which was also declared in her 2024 and 2025 statements of assets, liabilities and net worth (SALN).

Good faith

Castro also said Baste appeared to defend himself after Senator-judge Panfilo “Ping” Lacson brought up the Arias doctrine during the trial, asking the witness if he had been informed by his counsel regarding it.

“Parang lumalabas na pinagtanggol niya ‘yung sarili niya as a mayor. Inangat niya yung sarili niya as a mayor,” Castro said.

(It appears that he is defending himself as a mayor. He held himself in higher regard as a mayor.)

The Arias doctrine was established in a landmark Supreme Court ruling in 1989, which states that heads of offices can rely in good faith on the decisions and signatures of their subordinates when approving routine documents.

Castro noted that the Arias doctrine can only be invoked in an isolated case and cannot be used to cover up repeated anomalies or signs of irregularities that a public official should have noticed.

The Palace spokesperson also stressed that public officials should not use the doctrine to protect their own interests or hide potential negligence of their families and allies.

“Hindi lang ito para kay Mayor Baste Duterte. Sa lahat na po ng pinuno, dapat maging alerto rin kayo. Hindi pwedeng gamitin itong Arias v. Sandiganbayan para lang isagip ang sarili niyo,” Castro said.

(This is not just for Mayor Baste Duterte. To all head officers, you should be alert. The Arias v. Sandiganbayan cannot be invoked to save yourselves.)