The expected courtroom testimony of a former high-ranking Public Works official is drawing renewed attention to a multi-billion peso flood control scandal and the legal standards governing state witnesses in corruption cases.

Roberto Bernardo, a former undersecretary for the Department of Public Works and Highways (DPWH), is scheduled to appear Thursday before the Sandiganbayan Third Division.

His appearance comes amid persistent questions regarding whether his role in the alleged scheme aligns with the state witness doctrine, which requires that a witness not be the "most guilty" among those charged and that their testimony be indispensable.

Bernardo’s anticipated testimony has placed that legal standard under a microscope.

Multiple accounts previously presented in court have identified him as a central figure in transactions involving flood control projects spanning from Central Luzon to Mindanao.

While substantial public funds were disbursed for these projects, authorities say there has been no clear accounting of the actual outcomes.

The prosecution’s narrative suggests that decisions across these regions were coordinated through a common channel, which earlier testimony identified as Bernardo.

Henry Alcantara, a former district engineer and also a state witness, previously testified that he handed over approximately P1.8 billion to Bernardo. However, Alcantara admitted under oath that he lacked direct knowledge or documentation regarding the final destination of those funds.

Alcantara further acknowledged that many of his actions were based on personal assurances from Bernardo rather than verified records.

This reliance became a focal point for the bench, with Associate Justice Moreno noting Bernardo’s recurring role in the alleged scheme during a recent bail hearing.

The court raised concerns that subordinate officials may have followed instructions without sufficient verification, pointing to a chain of command that converges on a single figure.

These developments have intensified scrutiny of the prosecution's decision to use Bernardo as a witness.

While discharging an accused person to testify is a recognized legal tool, observers note it is intended to be applied selectively.

Bernardo’s credibility is also being questioned following reports of inconsistencies across multiple affidavits he has executed since Senate inquiries began last year.

Adding to the complexity of the case is Bernardo’s commitment to return up to P290 million to the government, an undertaking tied to his qualification as a state witness.

While the prosecution may view restitution as an act of cooperation, critics argue it reflects an admission of deep involvement in the financial transactions under investigation.

As Bernardo prepares to take the stand, the anti-graft court faces a broader institutional question of whether the prosecution’s reliance on his testimony strengthens the case or risks undermining it.

The proceedings are expected to test the limits of the state witness doctrine, particularly in cases where the line between a witness and a principal actor is blurred.