Yeah, it took the German justice system more than 70 years to come around the idea that assistance in genocide could be considered as assistance to murder, even if you can not be convicted for a specific killing and thus not fall under the statue of limitations. Certainly much longer than needed, but better late than never I suppose.
In meantime, many German leaders guilty as hell, high command
I don't know about that. Certainly far too many culprits went unpunished (it is estimated that roughly 250k were involved in the Holocaust, and from the survivors only a fraction was ever tried, let alone convicted), but the really high-ups often received some punishment, even if it only consisted of a few years in prison. None of the KZ camp leaders escaped for example.