No. Seized property is not automatically forfeited. Property can only be forfeited through the State process if the State wins a court judgment in its favor. If the State wins its case, ownership of the property goes to the State, and you permanently lose any and all rights to the property.
In our example, Steve's $900 was only seized, and is not yet forfeited. A forfeiture does not become final until the court signs a Judgment saying that the property is Contraband.