Very good answer. As an example the Patriots was broadcast by the local WBZ channel for the pre season game the other night, local programming was pre-empted. In fact whenever WBZ does this including for all of our victory National Champion Sports parades

that programming goes to a Super Channel I get, WSBK. A Connecticut channel did pick up the game but had it not there would have been no broadcast in Ct.
In the case of the OP, are you sure it was not on some channel there, a CW channel or independent channel, maybe even a Network channel? That would be a reason though the NFLN could carry it, it could not where you are.