Try to think of this from a practical stand point.
I keep thinking the descriptive word "Fork" is questionable when describing a P-38. Does any English source use fork tail when describing a P-38?
Note when searching other uses of the German word, you find "fork tail snapper." Fork, like "Fork in the road." and "fork tailed snapper" is a "Y" shape. I just don't think fork would be used as a common descriptive word for the twin booms in any language. One German might have used that description, but "The Germans . . ." as a whole, is very questionable.
Is there a German plane with a tail similar to the P-38? If so, how is it described?