Correct. All these things; home education, cultural sensitivities, undocumented claims of medical reasons for bruises/hunger/exhaustion etc etc, can be easily overridden and often are, when there are concerns about a child's welfare.
You don't hear about all the cases where they have been overridden and the family found to be fine, other good explanations for what looks at first glance to be suspicious found, or the concerns justified but not at a level requiring 'draconian' intervention. Many SW departments are doing it right even if it is awful for innocent parents who on closer examination can show the fears of others are incorrect, but it's not talked about because it's stigmatising being investigated.
You only hear it being trotted out as an excuse for failing to follow up, where a child has then died and so often procedure hasn't been followed and everyone from the ground upwards is looking for excuses and/or to bring their own agendas into play, in the name of not letting down another child whilst covering up their own failures over the last one.