His opinion is not controlling. He’s entitled to make his argument, of course.
Courts tend to uphold the “red flag” sort of process. Snooping, civil asset seizure, generally upheld. To the extnt courts object, they will give the red flaggers instructions of how to red flag with the courts’ blessings.
May, 2021 SCOTUS ruled 9-0 that Red Flag Laws are Unconstitutional. It’s settled.