Kat,I left that verse out by mistake when I first recorded it in the '70s. Then I just got used to doing it without that verse. Such are the workings of the oral tradition.
I personally feel that Billy or William or Willy or whatever, once he realized the lights were going out for him, laid the whole thing on Barb 'cause he knew it'd create, promote and accelerate a humongous GUILT TRIP that'd put her into therapy for the rest of her life. Ah, sweet revenge.
Art Thieme