I remember fishing Oak Orchard many years ago and snagged a bunch of zebra mussels which were attached to a small rock. Like you probably experienced, the current grabs the rock and it causes almost like a fluttering action which feels like a head shake in the current. I too thought I had a nice fish on for a few minutes only to realize a little later that wasn't the case. Now I wait for the fish to jump before getting excited! Rocks and zebra mussels will typically stay low in the water column

Dakota