According to John Welch, the speechlessness of Korihor (and to an extent the stunning of Sherem -- see Jacob 7:13-15) was precisely the kind of sign or restraint that people in the ancient Mediterranean world [and by extension the Nephite world] expected a god to manifest in a judicial setting when false accusations or unfair ploys placed an opponent at a distinct disadvantage [see the commentary on Alma 30:49].
What is interesting, in comparing this Mediterranean cultural practice with what is recorded in the Book of Mormon, is that stricken litigants often erected confession stelae. The inscriptions apparently were "a confession of guilt, to which the author has been forced by the punishing intervention of the deity, often manifested by illness or accident" In hopes of appeasing the offended god, a punished litigant would inscribe on the stela a clear profession of his newly admitted faith in the deity and would warn others not to disdain the gods.
The trial of Korihor (and that of Sherem) shows these same trends of confession. Korihor's confession acknowledged the power of God:
And Korihor put forth his hand and wrote, saying: I know that I am dumb, for I cannot speak; and I know that nothing save it were the power of God could bring this upon me; yea, and I always knew that there was a God. But behold, the devil hath deceived me . . . (Alma 30:52-53)
Sherem also acknowledged the power of God:
And it came to pass that on the morrow the multitude were gathered together; and he [Sherem] spake plainly unto them and denied the things which he had taught them, and confessed the Christ, and the power of the Holy Ghost, and the ministering of angels. And he spake plainly unto them, that he had been deceived by the power of the devil. And he spake of hell, and of eternity, and of eternal punishment. (Jacob 7:17-18)
[John W. Welch, "Cursing a Litigant with Speechlessness," in Pressing Forward with the Book of Mormon, p. 155]
Alma 30:56 He . . . went about from house to house begging for his food ([Illustration]): Thatched-roof huts are still the norm in Mexico and Central America. With the exception of the extension built on this house, which has been constructed of sawed boards, this hut near Izapa, Chiapas, would be nearly identical to a commoner's house two millennia or more ago. John Sorenson notes that nothing is said directly in the Book of Mormon about the houses of the Nephites, but a few inferences shed some light. That the city of Zarahemla "did take fire" (3 Nephi 8:8) from lightning (see 3 Nephi 8:7) confirms their perishable nature, especially of the roofs, no doubt made of thatch. [John L. Sorenson, Images of Ancient America, p. 60]
Alma 30:56 He . . . went about from house to house begging for his food ([Illustration]): A sketch of a house built in Yucatan sixty years ago shows the inside, with the roof omitted by the artist for the sake of visibility. It also demonstrates that the ancient custom of using little furniture has persisted even through centuries of Spanish influence. [John L. Sorenson, Images of Ancient America, p. 62]