One of the most challenging situations in litigation occurs when your own witness unexpectedly gives testimony that damages your case or supports the opposing party.

Even after careful witness preparation, this can still happen. A witness may change their recollection, become reluctant to testify, or simply provide evidence that differs from what they previously stated.

So, what should a lawyer do when this happens?

How Can Your Own Witness “Turn Against” You?

In practice, this situation may arise in several ways.

For example:

• The witness gave one version of events during the investigation but tells a different story at trial.
• The lawyer has no choice but to call a witness who possesses important evidence, despite knowing that the witness may not be entirely favorable.
• The witness changes their account from what they previously discussed with the lawyer.
• The witness begins giving answers that clearly support the opposing party.

These situations can significantly affect the outcome of a case if they are not handled properly.

What Is a Hostile Witness?

A hostile witness is not simply a witness whose testimony is unfavorable.

Rather, it refers to a witness whom the court considers to be adverse to the party who called them, or whose testimony materially contradicts previous statements or expected evidence, such that the court permits that party to examine the witness as though conducting a cross-examination.

Importantly,

A witness does not automatically become “hostile” merely because their testimony is unhelpful.

Whether a witness is considered hostile depends on the circumstances of the case and, ultimately, the court’s discretion.

What Can a Lawyer Do?

Under Section 177, Paragraph 6 of the Thai Civil Procedure Code, a party may ask the court for permission to treat its own witness as a hostile witness.

If the court grants permission, the lawyer may:

• Cross-examine their own witness.
• Ask leading questions.
• Confront the witness with prior statements or documentary evidence.
• Challenge the witness’s credibility where appropriate.

These procedural tools allow the court to better assess the reliability of the witness’s testimony and assist in determining the truth.

Practical Tips for Lawyers

When a witness begins giving unexpected testimony, it is generally advisable not to react immediately.

Instead, consider the following approach:

1. Allow the Witness to Complete Their Testimony

Interrupting too early may prevent the inconsistency from becoming sufficiently clear.

2. Apply to the Court

Once the inconsistency has emerged, ask the court for permission to treat the witness as hostile.

3. Explain the Grounds Clearly

The application should identify why the witness should be treated as hostile, for example:

• The testimony materially contradicts previous statements.
• The witness appears to be assisting the opposing party.
• The witness’s evidence significantly departs from the expected factual account.

If the court is satisfied that sufficient grounds exist, it may grant permission for hostile witness examination.

Why Is Timing Important?

Failing to seek the court’s permission at the appropriate time may limit the lawyer’s ability to challenge the witness effectively.

Without the court’s approval, the lawyer may be restricted from:

• asking leading questions;
• confronting the witness with prior inconsistent statements in the same manner;
• fully testing the witness’s credibility.

Knowing when and how to make the application is therefore an important aspect of courtroom advocacy.

Conclusion

A witness changing their testimony does not necessarily mean the case is lost.

Thai procedural law provides a mechanism for dealing with witnesses who become adverse after being called by a party. Where appropriate, the court may permit the witness to be treated as a hostile witness, allowing the lawyer to conduct a more robust examination.

The key is recognizing the situation quickly, understanding the applicable procedural rules, and making the application at the right moment.

Effective trial advocacy is not only about preparing witnesses for the expected—it is also about being prepared when the unexpected happens.

Siam Center Law Group Co., Ltd.

At Siam Center Law Group, we represent clients in civil, criminal, and family litigation throughout Thailand. Our litigation team provides strategic witness preparation, courtroom advocacy, and procedural guidance designed to protect our clients’ interests and present the strongest possible case before the court.