Retired Sandiganbayan Presiding Justice Amparo Cabotaje-Tang pushed back against defense lawyer Mark Vinluan’s question on whether she had been promised anything in exchange for testifying in Vice President Sara Duterte’s impeachment trial on Monday, stressing that her testimony is “not for sale.”

This came after the defense strongly objected to the prosecution’s bid to present Cabotaje-Tang as an expert witness for Article II of the Articles of Impeachment despite her not being listed as one in the pre-trial order.

Vinluan warned that allowing a “surprise witness” would violate rules on fair play and due process, but impeachment court presiding officer Chiz Escudero overruled the objection.

During cross-examination, Vinluan posed a series of questions challenging Cabotaje-Tang’s credibility, including whether she had received any offer in exchange for testifying.

“I will never testify if I ever was offered anything material or otherwise. My testimony is not for sale, sir,” Cabotaje-Tang said.

The retired jurist also denied seeking an ambassadorial post when asked by the defense, saying she had no plans to return to public service after retiring in 2024.

Vinluan also questioned Cabotaje-Tang’s alleged political affiliation with Akbayan Party-list, particularly her supposed ties with Rep. Chel Diokno, the prosecution’s co-team leader for Article II, which centers on allegations of Duterte’s unexplained wealth.

Vinluan pointed out that the subpoena for Cabotaje-Tang was addressed to Diokno’s office at the Batasan Complex, which he argued was improper because the task of serving subpoenas rests with the impeachment court.

Cabotaje-Tang, however, said that while she received the subpoena through Diokno’s office, it was sent by email and not personally delivered.

“Under the rules, isn’t the court’s duty to serve the subpoena?” Vinluan asked.

“Yes, but sometimes the court designates another person to do it,” Cabotaje-Tang replied.

Vinluan maintained that Diokno had no authority to serve the subpoena, regardless of whether it was sent by email, because he had not been properly designated by the court.

Cabotaje-Tang also denied being connected with Akbayan after Vinluan presented a photograph that supposedly showed her and Diokno attending a UP Law-organized event.

Diokno moved to correct Vinluan’s statement in the record, saying, “I do not see myself in the photograph.”

The prosecution maintained that Cabotaje-Tang’s testimony was crucial in determining what may constitute unexplained, hidden and ill-gotten wealth under Article II.

Vinluan, however, argued that Cabotaje-Tang should not be qualified as an expert witness, saying that interpreting the law was the function of the impeachment court.

“Whatever opinion that she will share with us today is not an expert opinion but her personal opinion. And that is the danger of presenting her, because she might present her own interpretations of the law, again, which is the function of this court,” Vinluan said.

Escudero overruled the objection, saying Cabotaje-Tang’s testimony was neither conclusive nor binding on the impeachment court and remained subject to cross-examination by the defense.

Cabotaje-Tang spent 44 years in public service. After passing the Bar in 1980, she joined the Supreme Court as a judicial assistant for two years before moving to the Office of the Solicitor General, where she later became assistant solicitor general.

She served at the OSG for 31 years and, as former chair of its task force, handled ill-gotten wealth and civil forfeiture cases involving money laundering.

Cabotaje-Tang was appointed Sandiganbayan justice in 2012 and became presiding justice a year later, a post she held until her retirement in November 2024.