Nice eye Evan, it's incredibly hard to spot something like this especially when there's only one or two videos actually showing it. You can see glimpses of it throughout the ride, but you get the best look at 0:53.
I heard about FoF having fracturing issues over the years due to the stress, but I had no idea they replaced parts of the ride with pieces of another coaster. So far it looks like it's only one or two pieces, but I can't help but think that there's more that were repainted before being put in...
I wonder if Kings Island's Flight of Fear also uses some of the pieces from Mad Cobra...