I think you might argue that the a in bade is stressed whereas the a in made is unstressed? Otherwise I agree, there’s no difference between the two in my dial

I think you might argue that the a in bade is stressed whereas the a in made is unstressed? Otherwise I agree, there’s no difference between the two in my dialect. Wiktionary suggests that it can be a homophone with bad in some dialects though, so perhaps that’s what the author was thinking of?