After his mom called the police, they took his shotgun that he owned at the time but never had his hearing because apparently if they couldn't prove he was a danger, they would have to give his shotgun back but nothing in the law prevents him from buying subsequent firearms. As any idiot can get a credit card it was likely no problem for him to buy a couple of ARs, which he did buying a Ruger 556 and a HM Defense HM15F (never heard of that). So out of fear of him getting his .410 shotgun back, they didn't have the hearing so he was able to legally purchase to rifles.
Here is the kicker from the article from Ryan Mears, the prosecutor for Marion County:
After explaining the steps his office did and didn't take, Mears again pointed to what he sees as limitations in Indiana's red flag legislation. He says it has been an issue he has raised both publicly and privately over the years.
He would like to see the law changed to prohibit individuals from buying weapons the moment a red flag petition is filed, and he would like to see the 14 days window extended.
You can bet that this incident will be used as an excuse to make Indiana's already onerous red flag law even more stringent and remove more of the due process involved in taking someone's firearms.
This kid was clearly nuts and Hole is the kind of person that they always talk about using red flag laws on but red flag laws will invariably be used against political opponents and dissidents. It starts to make sense now.