You're doing what I mentioned some time ago should be done by a serious researcher interested in Black Confederates -- search first-hand Southern and Confederate sources. Why they've been ignored by SCV and Southern heritage groups sponsoring nearly all the BC websites, I cannot imagine.
The newspaper source for the "battalion of negroes" who served under Forrest in the raid on Murfreesboro is at best a second or third-hand source. Forrest's famed escort is often claimed as an integrated unit, but on examination of first-hand sources, we know this to be untrue. In any case, the company formed as Forrest's escort did not organize and report to his command until October 1862, several months after this event.
Any second-hand report has to be examined in light of first-hand reports. Obviously you would review General Forrest's own report of the Murfreesboro raid, and any other Confederate reports. The Confederate leader's report of the action can be found in the Official Records, Series I, Vol. XVI, part 1, pages 810-11. The first paragraph covers those units under Forrest's command --
We left Chattanooga on July 9 with the Texas Rangers, under Colonel Wharton, and the Second Georgia Cavalry, under Colonel Lawton. We made a forced march of nearly 50 miles, reaching Altamont on the night of the 10th instant. After resting one night we passed on to McMinnville, where I was joined on the night of the 11th by Colonel Morrison with a portion of the First Georgia Cavalry, two companies of Colonel Spillers battalion, under Major Smith, arid two companies of Kentuckians, under Captains Taylor and Waltham. After this junction my whole force was about 1,400 men, and both men and horses were much jaded and worn by their long travel. After feeding and refreshing for a single day and being joined by some few volunteers, I left on the 12th at 1 oclock for Murfreesborough.
We have the 8th Texas Cavalry, 1st and 2nd Georgia Cavalry, Lt. Col. C. C. Spiller's Tennessee Cavalry, plus Kentucky cavalry companies under Capts. Taylor and Waltham. These can be confirmed by first-hand accounts by Confederates who served with each of these commands. An example would be the wonderful account of this attack in Wyeth's "That Devil Forrrest." There are numerous first-hand accounts for the 8th Texas Cavalry alone.
After exhausting Confederate accounts for this action, we might review Federal reports by those who were actually present and surrendered to Forrest. Do they mention any "battalion of negroes"? At this point we know the news report is flat wrong. You're left with the question - why would anyone have thought that Forrest led a Black Confederate battalion in this raid? If the news report had mentioned a battalion of Canadians or South Africans, wouldn't we ask, what could the reporter have in mind?