Lenin - the thing is when people talk of mistakes happening, unless you are aware of how the system works it is difficult to understand. You sound reasonable so I will try to explain.
If a child is removed from a parent and this is always a last resort, then the matter has to go to court for a decision by a judge. There are numerous lengthy assessments undertaken of the whole situation, by social workers, guardians (ind sws appointed to be the voice of the child in court )pyschologists, sometimes psychiatrists, sometimes paediatricians etc etc. Before a case can be presented in court it has to be proved that EVERY attempt has been made to do everything possible to enable the child to be reuntied with the family. Any sw knows that unless they can prove this to a judge it is no use going to court, as the case will be thrown out by the judge.
Sometimes parents are given the opportunity of a residential assessment where they can care for their child but are monitored as to whether the child is safe in their care and the workers also produce reports.
The parents are assessed by psychologists and psychiatrists if there are mental health problems and all reports have to make recommendations based on the best interests of the child, not the parents. In addition if the lawyer for the parents feels that the parents are not being given a fair chance, they can request that the court appoint a completely independent sw to do a parenting assessment. (I work as an ind sw and get involved in doing these
All of this takes many months and if the parents can improve their parenting, make good use of the support on offer etc then the proceedings can be stopped and the child returned to them. Sadly this is often not the case and the concern for the child is such that the matter must proceed in order to protect the child.
All of the reports have to give a recommendation on what is best for the child's future. Then the matter goes to court and the final hearing takes 4/5 days and everyone who has made a report has to given evidence to prove what they are saying about the parents and the child and why they feel the child is not safe with the parents (if that is what they do think) if they think something differently then they say so. The solcitors for the parents cross examine all the people who have made reports and this can take 3/4 hours. SO you have to be able to evidenc what you are saying.
At the end of it all the judge makes the final decision.
If you are interested I can tell you about why fostering or adoption is planned if the child is not going to be returned to the parents. However I have been caught on these threads before when I give a lot of info only for people to come on and insult me, so I am a little wary.