2 cents worth of "take it or leave it" observations from a long-time textiles guy, about the fabric "damage" to the single ribbon. Take a close look at the "warp" in the weave and you'll see why the flaw can be isolated to the one ribbon. The fabric, with age, has simply parted, probably due to an imperfection found in any looming process, perhaps a "slub," a soft thick nub in the yarn that loosened with age. In other words, the yarn has parted; it has not necessarily been "nicked." More conjecture: maybe the pin in the swords loosened the slub when it penetrated the weave. . .
And take a closer look at the fabric just above the "part." It appears that aomeone with dirty fingers tried to "pinch" the fabric back together!