That's interesting. The word 'Sonderkommando' has no negative connotation at all in German. Is it something specific to how the British look at WW2? Or is it just the usually outrage between parties?
The Sonderkommando was a special group of prisoners at Auschwitz who had to prepare and cleanup the extermination of millions of prisoners. Their job was to carry the dead from the gas chambers into the ovens. They were recycled every 3 months or so by a fresh Sonderkommando, whose first job was to murder their predecessors. They also made history by starting the only counter-attack at the camp, blowing up one of the gas chambers.
You can write "Deutschland ueber alles" all day, that's a minor issue. But using Sonderkommando in the wrong context can cause quite a stir.