It's interesting that, under the existing skating system rules, a couple can win even though they are placed first by fewer judges than the couple placed second. If they're placed equal, then rule 11, as explained by Ladydance, is used. Rule 11 can be applied for any place, of course, not just first.
Research papers have been published on the skating system. It has been known for some time that a method based on the 'median' of placings is much fairer. But this was harder to calculate with pencil and paper at the time the present rules were introduced. Of course it's all done via software these days but then the international dance organisations would have to come to an agreement.... .