Was lucky enough to meet Bill on a couple of occasions, he was an absolute gentleman and will be sadly missed. I've got one of his crib sheets that he used for his commentaries, you would not believe the amount of (handwritten) detail he had on their about each of the players, subs, coaches, refs, physios etc etc, he really knew his stuff.
As others have said if ever you picture a passage of play in your head, it's him doing the commentary. Legend.