Okay, so the KB podcast was a month ago. Give me credit for finally catching up.
My favorite part of the Kill Bill movies was the Hanzo scene, because QT didn't feel the need to explain anything. The bride merely had to tell him which rat the sword was for and his convictions went out the window. Many writers/directors would have felt the need to add a flashback to explain the Hanzo/Bill history, but QT lets inference tell us everything we need to know.
Of course, it's entirely possible that just such a scene was made and dropped for time purposes (although if so, it probably would have ended up in the extras and I don't recall it being there). If so, QT was wise to drop it.