A moral absolutist would argue that most, or even all, are wrong in one way or another. One can be a moral absolutist without claiming to be able to evaluate the morality of any particular scenario.

To provide an analogous example, there is a two-player game called Hex for which it has been proven that there exists a dominant strategy for the first player, but a generalized winning strategy is unsolved. One can soundly assert that such a strategy exists without knowing what it is. Likewise, its not fundamentally invalid to assert that there exist absolute moral truths without knowing what they are.