It's a county-owned phone. Farook didn't own it nor pay the account. Thus, the "account reverting Apple" wouldn't apply.
I'm suspecting that there may be some law action requiring that employees will need to supply their passwords on all company or government owned equipment.
Where I work, if an employee terminates, they can take the phone with them. If they choose not to, we ask for the login to unlock it and clean it for the next user. If the employee dies, we're up the creek and phone gets tossed.