Was There a Slave Jury System at Jefferson Davis's Plantation?

In my readings I have run across occasional references to the slave jury system that Jefferson Davis and his older brother Joseph instituted at their neighboring plantations at Davis Bend in Mississippi. Here, for example, is Eric Foner's description, from Reconstruction: America's Unfinished Revolution, 1863-1877:

. . . Davis Bend, a peninsula formed by the tortuous course of the Mississippi River just south of Vicksburg, which contained the huge plantations of Confederate President Jefferson Davis and his brother Joseph . . . had already been the site of one utopian experiment before the Civil War. Influenced by Joseph's encounter with British socialist Robert Owen, the Davis brothers had attempted to establish a model slave community, with blacks far better fed and housed than elsewhere in the state and permitted an extraordinary degree of self-government, including a slave jury system that enforced plantation discipline. Other planters mocked “Joe Davis's free negroes,” but the system enhanced the family's reputation among blacks. After the war, one group of Mississippi freedmen pressed for Jefferson Davis's release from prison because “altho he tried hard to keep us all slaves . . . some of us well know of many kindness he shown his slaves on his plantation.”

As you will note, Foner admits of no uncertainty concerning the Davis brothers' “utopian experiment” and its central feature, the “slave jury system that enforced plantation discipline.” There is even a story line and explanation of the origin of the system. “Influenced” by “British socialist Robert Owen,” Joseph and his brother”attempted to establish a model slave community” as a “utopian experiment.”

In his fine biography of the Confederate president, Jefferson Davis, American, William J. Cooper, Jr. concedes that the available evidence does generally confirm that the Davis brothers “were benevolent masters for their time and place.”

[B]ut the familial story goes considerably further in holding up the Davis brothers as model masters running plantations on which the slaves barely realized they were slaves. According to this script, Joseph set the pattern of an unusually humane system, which his youngest brother and protege followed. A key element in this version of slavery both at Hurricane [Joseph's plantation] and Brierfield [Jefferson's plantation] involved the slave jury, where any slave accused of violating a plantation regulation was tried by a jury of his peers, that is, by other slaves. The master intervened only to ameliorate harsh sentences, as when Jefferson supposedly reduced a penalty of 5,000 lashes to an extra hour in field. In the same vein, the whip, the pervasive symbol of white authority in the slave South, was unseen, for Jefferson forbade corporal punishment, specifically whipping.

Prof. Cooper points out, however, that the “slave jury” story is thinly sourced, and that there are reasons to doubt its veracity:

This view of slavery under the Davis brothers originated with Varina [Davis, Jefferson's wife] in her Memoir, published in 1890, and in her subsequent correspondence and in letters written by Joseph's granddaughter almost two decades later [an accompanying footnote cites letters dated 1905, 1907 and 1908]. Although the two women should certainly have been excellent witnesses of slavery at Brierfield and Hurricane, they were both looking back from the late nineteenth and early twentieth centuries, when southern whites were romanticizing old plantation days, including slavery. Additionally, no other contemporary documents verify this plantation Eden. That such a fascinating system of slave management run by two such prominent individuals in such an accessible location completely escaped notice is puzzling.