MILAGROS MANONGSONG, etc., et. al. vs. FELOMENA JUMAQUIO ESTIMO, et. al., G. R. No. 136773, June 25, 2003
“x x x.
Petitioners admitted before the trial court that Navarro was the mother of Guevarra. However, petitioners denied before the Court of Appeals that Navarro was the mother of Guevarra. We agree with the appellate court that this constitutes an impermissible change of theory. When a party adopts a certain theory in the court below, he cannot change his theory on appeal. To allow him to do so is not only unfair to the other party, it is also offensive to the basic rules of fair play, justice and due process.
X x x.”