The case as I have briefly read about it is a guy in Pennsylvania was arrested for a DUI back in 2002. His case was apparently not listed as a felony and he even had his case dismissed because he entered into a voluntary rehabilitation program prior to adjudication.

None the less in 2016 he was denied the right to purchase a firearm and was informed that he was permanently banned forever from owning a gun.

Even the District Court ruled that, "Holloway’s DUI offense was a non-serious crime that has not historically been a basis for the denial of Second Amendment rights"

This is just a basic synopsis of what I have found so far, but apparently the case will be taken up in the SCOTUS to determine if a non violent crime can be used for a permanent denial of 2A rights.