I had the very same reservations, so I pulled the actual bill. If it passes (& it hasn't yet), the procedure looks something like this:
- Doctor makes diagnosis of mental illness;
- Doctor must report same to county prosecuting attorney, if person is an immediate danger to self or others and should not possess firearms;
- Prosecuting attorney files petition with circuit court requesting a search and seizure for and of firearms;
- Court appoints public defender to represent patient;
- Court holds hearing involving both prosecution and defense on the petition;
- Makes determination on petition and what should happen with firearms and ammunition, if seized;
- After one year, person diagnosed may petition for return of firearms, if they were not destroyed.
There are a few other wrinkles, but that's the basic framework.