It's happened a few times, but it would only be ridiculous if every team had played the same number of games against the same opposition, which of course they hadn't.
Personally, as long as we have the split, I'd maybe rather they just split the league into two groups proper when the time comes, instead of pretending that everybody's still playing in the same league afterwards. Perhaps even start the bottom team in each group on zero points, with the other teams' points adjusted accordingly. At least that would stop people moaning about the fact that the team in 7th occasionally ends up with more points than the team in 6th (as if that really makes any difference, when everybody knows and understands that it might happen before a ball is even kicked).