I think the two meanings of "oversight" are not quite interchangeable. One is a mass noun (used without an article): "better oversight is needed"; while the ot

I think the two meanings of "oversight" are not quite interchangeable. One is a mass noun (used without an article): "better oversight is needed"; while the other is a count noun (used with an article): "it was an oversight". So "because of oversight" sounds odd to me; I think it would be "because of an oversight", which would unambiguously indicate the "error" sense.