The great Litvishe Gadol the Achiezer, Rav Chaim Ozer Grodzinski [4-94] wrote that if the Sotah was given her Mincha on condition that she not be מפגלת, if she is מפגלת then it will turn out that she didn't keep the condition and the Mincha was thus not hers and one has no right to be מפגל a Korban belonging to someone else. However, if we say that she wasn't successful in being מפגלת the Korban then it turns out that it WAS her Korban. But if it was her Korban then the פיגול takes effect.
So we go round and round ad infinitum.
So therefore we say that since if she is מפגל there is no פיגול - there is no פיגול and the Korban is hers. As we said - you can't have a חלות that contradicts itself.
The great Chasidic Rebbe the Divrei Chaim concurs [ח"ב או"ח ט"ז]!!
So this is a BI-PARTISAN issue!!
