I think that's a stretch. Sonny used the term Japs and Jap-lover indicating a degree of racial or ethnic prejudice or, at best, some dissonance over his country being attacked.
I might suggest a very small degree of prejudice. There were other terms that were more racially motivated. Jap, at that time was sort of slang for a Japanese person. For those old enough to remember Oriental back then was perfectly acceptable to use, but now to be PC, the term "Asian" is preferred. So from now you call your rugs, not the ones on your head, Asian rugs instead of Oriental rugs.
