Update and summary of the forgoing:
In the Case of Bayot vs CA (G.R. No. 155635, November 7, 2008):
"Three legal premises need to be underscored at the outset. First, a divorce obtained abroad by an alien married to a Philippine national may be recognized in the Philippines, provided the decree of divorce is valid according to the national law of the foreigner. Second, the reckoning point is not the citizenship of the divorcing parties at birth or at the time of marriage, but their citizenship at the time a valid divorce is obtained abroad. And third, an absolute divorce secured by a Filipino married to another Filipino is contrary to our concept of public policy and morality and shall not be recognized in this jurisdiction."
Additionally the Court ruled re: how a divorce decree obtained abroad could operate as res judicata in This jurisdiction:
"Before our courts can give the effect of res judicata to a foreign judgment [of divorce] x x x, it must be shown that the parties opposed to the judgment had been given ample opportunity to do so on grounds allowed under Rule 39, Section 50 of the Rules of Court (now Rule 39, Section 48, 1997 Rules of Civil Procedure), to wit:
SEC. 50. Effect of foreign judgments.--The effect of a judgment of a tribunal of a foreign country, having jurisdiction to pronounce the judgment is as follows:
(a) In case of a judgment upon a specific thing, the judgment is conclusive upon the title to the thing;
(b) In case of a judgment against a person, the judgment is presumptive evidence of a right as between the parties and their successors in interest by a subsequent title; but the judgment may be repelled by evidence of a want of jurisdiction, want of notice to the party, collusion, fraud, or clear mistake of law or fact.
It is essential that there should be an opportunity to challenge the foreign judgment, in order for the court in this jurisdiction to properly determine its efficacy. In this jurisdiction, our Rules of Court clearly provide that with respect to actions in personam, as distinguished from actions in rem, a foreign judgment merely constitutes prima facie evidence of the justness of the claim of a party and, as such, is subject to proof to the contrary."