Yeah, my example isn't exactly correct, but it's generally correct (i.e., the reason the assets were not returned notwithstanding the overturned convictions is because of the different standard of proof required for civil asset forfeiture).

The burden of proof for civil asset forfeiture is actually lower than the burden of proof for obtaining a judgment in a civil case, and there is no trial (unlike the OJ civil case). The test is (generally stated) whether police believe based on a preponderance of the evidence (as opposed to clear and convincing evidence, my error made above) that the assets are fruits of a crime, the burden is on the defendant to show that they are not fruits of a crime. In Massachusetts, the standard is that police must show probable cause to believe that the assets are fruits of a crime, a very easy threshold to meet.

>As there was no civil case that allowed the seized assets to be kept by the government, they should be returned.

I agree with you in principle, because I think civil asset forfeiture is a taking and should be subject to due process of law. Unfortunately for those who do not support civil asset forfeiture, the U.S. Supreme Court has repeatedly upheld it's constitutionality, so it isn't going anywhere (unless the Court changes its mind).