I've been through a false report and a law court failure. Granted its not in the UK but just like in the UK, all the professionals - social workers, doctors, lawyers, judges - are human beings, some good, some bad, some over zealous, some lax, some acting from bad intentions, most from good. So my experience is most likely very similar to others'
A doctor, a respected paediatrician, made a false report that I was being physically abusive to toddler DD, even saying that I had openly admitted it (the report was the idea of my ex and his parents, not sure if the doctor knew it was lies or just very gullible, inclined to believe the former though judging by his later actions) so SS told me I needed to take her to the doctor (same doctor, I didn't realise it was him at the time) he told me that DD has epilepsy and told me to take her to the hospital but added a secret note to the referral that it was for child abuse.
We went through 4 days of testing, including full MRI and a special kind of eye test that looks for signs of brain injury. I was of course terrified throughout. Wasn't allowed to take her out of the hospital, was questioned thoroughly several times by doctors. Ex's dad, once it was clear that the testing was showing no signs of abuse (no new or old injuries or anything like that) changed his accusation to sexual abuse so had to have DD stripped naked and examined, and later on had to take her to a different hospital for a sexual abuse examination where they take photos and everything. All through this I course knew I was innocent but was also terrified that if one doctor could make a false report, perhaps others could, but they didn't, because doctors and nurses in a hospital are under much more scrutiny than a private paediatrician.
By midday on the 4th day the hospital and the social workers were happy to discharge DD into my care and then I had the legal system failing, where a judge decided to issue an emergency order without bothering to contact either the social workers, or the hospital (so an example of a professional who just couldn't be arsed to do their job properly because it was Friday afternoon and he wanted to go home, that was literally his excuse) and I had DD taken away from me by my ex for two excruciating weeks. But the system still worked. Even though parts of it failed temporarily, the system as a whole worked, as the social workers called the judge and railed at him for not doing his job properly, the judge looked into the evidence and realised he made a mistake and the order was revoked and I got DD back.
It was traumatising, especially for DD, but I'd still rather the social workers took that initial report seriously than assume it wasn't real (they had an idea that it was something cooked up by my ex and his parents because they had been making reports for months about ridiculous things) because what if it was real and a child really was being hurt. And even putting aside the whole abuse accusations, what if DD really did have epilepsy but I refused to take her to the doctor out of fear of what might happen?
I strongly believe that every child should have at least yearly check ups, to help spot signs of abuse or neglect, as well as spot early symptoms of disease and illness. Precisely because some parents are afraid to take their children to the doctor out of fear of 'baby snatchers' so the chances of a medical issue being missed increases.