Are the team genuine heroes? Or are they war criminals?

I know, it is traditional to show members of the French Resistance, and SOE agents, as heroes, even when they actively engage in hostilities.

The Germans didn't always comply with the Geneva Conventions. Hitler had a secret "commando order", ordering the extrajudicial execution of commandos like the captured canoeists who snuck deep into a French estuary to plant time bombs on the German vessels moored there.

However, the Germans would have been entitled to try the SOE agents as war criminals. They were not wearing German uniforms as a "ruse de guerre", in a way that complied with the Geneva Conventions and the accepted "laws of war".

The old blockbuster film, The Battle of the Bulge shows the Germans sending special squads of English speaking German volunteers, wearing US uniforms, were sent behind American lines. The Germans did send twelve jeeps with English speaking Germans behind American lines.

The unit was under the overall command of a famous German Commando leader, Otto Skorzeny. He regarded it as a suicide mission, but German military lawyers assured him that driving American jeeps, wearing American uniforms, was a legitimate ruse de guerre, provided the German soldiers made sure they took off the American uniforms and put on German uniforms, before they fired back at any Americans who fired at them. Most of these volunteers seem to have been given (illegal) summary battlefield executions. One jeepload of Germans was court-martialed and executed.

After the war Skorzeny, a bona fide Nazi, faced war crime charges. It turned out his tribunal agreed with the original German military lawyers, and Skorzeny was acquitted.

But the SOE agents in episode one did fight wearing captured German uniforms. Under the Geneva Conventions this is called "perfidy".