Only a policeman knows what goes on in the real world, the belief that such things never occur in the UK is false I'm afraid.
To put the Leonor Cipriano torture into perspective, it was more of a mild beating with a cardboard roll than a torture. You have to understand the circumstances to fully comprehend why several detectives put themselves in that position.
A youngster was missing and a mother and uncle were admitting to foul play but refusing to say where she was located or at least were giving false indications.
Do you not think that in those circumstances something needed to be done quickly in order to have any chance of finding her dead or alive? It was a case of do something and do it quickly.
Was a child's life not worth a few bruises?
What makes you think that they were looking for a living child? The GNR had searched for her; the initial PJ team in Portimão had been trying to follow up potential leads. Then big boots from Faro came in and wafted a black torch around and decided the child had been murdered for some inexplicable reason. If that had happened there was no child to potentially save.
I find that there's a difference between really wanting to get to the truth of the matter and simply wanting to get a conviction, irrespective of whether the person is the real perpetrator or not.
I do take the more general point of tense time-sensitive situations that the police must face from time to time - hostages, a bomb about to blow up, etc., but then a modern police force would have a massive crisis team checking out and cross-checking every bit of information and specialist officers trained in getting information out of suspects in dynamic situations.