It was in the beginning of the film and when the German bomber crews go to explain why they bombed london;)
But to be honest the CASA aircraft did not differ massively from their German counterparts except in engines and some equipment so does it really matter if they are wolves in sheeps clothing?
I would like to see the CASA HE111 in German markings as it is mostly a HE111except for in its place of birth and bits, same with the JU52 and the buchons.
curlyboy