The phrase khai khadi is Thai for solving or unravelling a case, which explains how this clip is used online rather than any confirmed source recording. Its origin is not documented in the listing, so creators treat it as a ready made detective cue in the same family as a dun dun dun reveal. It spread through short edits where a narrator style investigation is played for laughs, and it remains useful because the case solving idea is understood instantly, even by viewers who do not speak Thai.