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It was oregano, Dave, it was ten dollars worth of oregano.
— Kaffee ‧ A Few Good Men

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The repeated naming of oregano makes the correction emphatic, while the exact price adds a deliberately ordinary detail. Addressing Dave keeps the statement conversational. Its force comes from insisting on what the substance actually was, as though that distinction should settle the matter.
Context reviewed