I'm fairly certain that when assets are forfeited any party has the opportunity to claim the property. There is no case where no claim is found valid and law enforcement gets to keep it.
From wheat I read, police have been pulling people over, and if there is cash in the car, "suspected" it might be used for drugs (even though the accused claims it's for other reasonable purchases) and then the person doesn't get the money, even after making a claim to get it back.
In your example it's not forfeiture, it's evidence. Evidence treated differently. It's either held until a verdict is reached or it's returned to its rightful owner.