I see it as a Lady or the Tiger situation. In fiction we generally expect the rules to come out ( magic A = magic A ) and then be consistently followed. But Dick is notorious for subverting or applying recursion to the same reality-altering notion.
We've seen this happen in other Dick stories. In impostor for example, Spence Olham is triggered by realizing he is not human.
If Deckard is a replicant it is possible he's not aware of his inhuman status and that neither are his fellow officers. Even Rachael brought up the point that the hunters are not expected to get tested, themselves.