I think this non-rule arose because the girl and others misunderstood the actual rule.
What sucks is, even though it's good sense to establish rules beforehand, it's hard to imagine ironing out ALL the weird local rules that bangers come up with. With people who can actually play it's pretty easy... ("BCA rules? OK.") ...but with this chick, what would the conversation be like?
"OK, before we play, I just want to nail down a few things. You play ball in hand or behind the line? OK, what about scratches after the break? Take what you make, or open after the break? Are combos legal if it's open after the break? How about comboing with the 8? Call shot or slop counts? Do I have to call the obvious ones? What about combos and banks? OK, and the 8? Do shots have to go clean or is it ok to bump other balls on the way in? What if I graze the rail? Are safeties allowed? Do I have to announce them? Can I make a ball while playing safe or must I shoot again? Does something have to hit a rail after I hit a ball? What if the ball is frozen to the rail? What if I nudge a ball with my hand or with the stick? Can I cradle a ball with my hand so I can bridge over it? Can I use a jump cue? Are masse shots allowed? Are you allowed to make a spacer the width of your cue's butt between the CB and rail? How do I rack 'em? 8 on the break count? What if I scratch, is that a loss?... ."
Forty five minutes you've nailed down one local's version of the rules and you can now start your match.