I know you don’t understand, that’s obvious. Read some law, Get behind the concept of “burden of proof’. Read the OJ story- he was acquitted of Murder as the defense was able to show 'reasonable doubt” but was found liable in a civil lawsuit as the “preponderance of evidence” showed he was guilty.
In order to be found guilty of a crime, it must be proven *beyond all reasonable doubt. * This is a very high burden of proof, much higher than a civil or procedural matter.
Thus is is very easy for it to be simultaneously true that the cops apparently behaved improperly (more evidence than not), and are not guilty of manslaughter (must be proven beyond all reasonable doubt).
Appropriate user name, tho.