It was to protect the police (top brass, they'd have thrown the bobbies under a bus), the FA who held such a big match in a stadium whose away end was known to be far too small/not enough turnstiles, the council, no safety certificate etc...
Establishment arse covering. It was a bonus to them that it was predominantly Liverpool families, the Tory government hated them. Duckenfield gave a bad order to open gate C without anybody directing the fans to empty pens, he realised what he had done and the cover up was underway while people were still dying.
He said fans rushed the gates, so to perpetuate that lie he refused to let a fleet of ambulances which were OUTSIDE onto the pitch as he said they were still "fighting". Initially it was thought 41 could have been saved but the estimate is closer now to 58 (I think) there were ambulances outside (keep letting that sink in).
Kids like Kevin just needed a tracheostomy. He died, as did many others when they would have survived.
How is that not manslaughter? Easy. They were Establishment. The law doesn't apply.