When the Germans are using dogs to trace the commandos there is a lot of barking added to the soundtrack. The dogs aren't actually seen barking and they wouldn't be in reality. Military dogs would be trained to remain silent.
When the commandos are hiding under the road some German troops are marching in formation before other Germans come following them in combat readiness. It makes no sense to have one group go first in a tight formation if there is a search going on. Also we soon learn that there are mines nearby, which would also hamper the German search efforts greatly.
German tanks are actually M47 Pattons, a postwar US model.
During the raid on the airbase, as the planes are blowing up it is clear the planes are models and the flames are too big for the model scale.