There has been a succession of cases over the past 20 years in which social workers have given a less than professional service. Families have been disrupted, children have suffered yet there is no recourse against the negligent social worker. A specific example would be the "Satanic abuse" fiasco which arose in Scotland some 20 years ago. Other professionals can be called to account for their actions, social workers can not. Good social workers would have nothing to fear if the crown immunity was removed; the negligent and unprofessional would most possibly leave the profession or at a minimum adopt a more proffesional attitude to their work.
Most professional people are subject to civil action if their work is negligent. The effect of this is to focus the mind wonderfully so that the risk of giving an inadequate or negligent service to a client is minimised. The service to the client benefits. Social workers are not subject to this risk. If a social worker is negligent then the offended party has no recourse to the courts. A negligent social worker is subject to internal discipline alone. This does not encourage a professional attitude since the social worker is protected from the consequences of their actions.