Catching up on Season 1 now. Doesn't really get going until Ep3, then we get the massacre of the German airmen and ground crew in the mess hall while unarmed and inebriated, with no chance to surrender. It appears from Googling this actually happened so not putting in a spoiler, but the legality of what they did must be questionable, even for the SAS. If German commandos had done similar to a British base and those responsible traced, would surely have been categorised as a war crime and someone might well have ended up on a trapdoor with a noose around their neck...