They dont have a second amendment in Australia I dont believe.SHALL NOT BE INFRINGED!!
Whether he gave them up or he didn't that's not the issue he doesn't have to as no laws were broken in other words he wasn't a criminal. Red flag laws are just a side step for the gubment. Take them to court
In fact they pretty much collected all the guns in 1996.
Its always surprising to hear someone owns guns, reloads, and hunts in Australia. Sure aint in the cities.