«إِنْ شَهِدَ لَكَ عَدْلَانِ مِنَ الْمُسْلِمِينَ وَإِلَّا فَاسْتَوْفِ مِنْهُ الْيَمِينَ»
If two upright Muslim men testify for you, present them; otherwise require his oath.
The governor calls for two upright witnesses or, failing them, an oath. The sequence distinguishes an accusation from the evidentiary steps through which it might be assessed.
Because the allegation is later exposed as a trick, procedure matters to the plot. Still, one dramatic exchange cannot stand as a full legal code for homicide, compensation or judicial practice; those questions require separate sources.