This is wildly off-topic, but a prosecutor asking for a defense witness to be "treated as hostile" is redundant. They're hostile by default.

The request to "treat someone as hostile" is about their OWN witness that THEY introduced getting turned into a hostile aka opposition witness.

> A hostile witness is a witness who testifies against the party who has called them to testify. The examiner may ask a hostile witness leading questions, as in cross-examination. Also known as an adverse witness.

As I said, a witness from the other side is always hostile, so asking for it would never make sense.

To give an example: Criminal case, prosecutor brought in a on-scene witness to testify. But the witness is arguing against the prosecutor's case/evidence, so they request the judge to allow them to turn a witness hostile which allows a different style of questioning.