Curiously I first heard those terms in Microsoft's Combat flight simulator when flying Luftwaffe aircraft. I wondered at the derivation at the time. Naturally the British terms get an airing too. The 'Indianer' cry I found rather touching really. Most WW2 pilots were little more than boys after all, on every side.
I have often wondered at the feelings of the WW2 Luftwaffe pilots who joined the post war Luftwaffe,particularly when they visited the Britain on course or exercises or whatever. It must have been rather odd. I must buy Rall's book.