Christian Prophecy More Necessary Than Ever

Charlotte Allen has an op-ed in yesterday's WSJ on gay totalitarianism. First the background:
On Tuesday the Supreme Court heard oral arguments in Obergefell v. Hodges, the case that asks whether the Constitution requires states to allow same-sex couples to marry. Four days before the hearing, in Oregon, an administrative-law judge proposed a $135,000 fine against Aaron and Melissa Klein, proprietors of the Sweet Cakes bakery in Gresham, for the “emotional distress” suffered by a lesbian couple for whom the Kleins, citing their Christian belief that marriage is between a man and a woman, had declined to bake a wedding cake in 2013.
But then this jumped out at me:
Same-sex marriage wasn’t legal in Oregon [my emphasis]when the Kleins made their decision. But the couple was found to have violated a 2008 Oregon law forbidding discrimination in public accommodations on the basis of sexual orientation.
If same-sex marriage wasn't legal at the time the Kleins refused to bake the cake, I don't understand why the finding against them isn't an ex post facto law. How are they legally obligated to be more progressive than the law?