G.R. No. 203806 - Municipality of Famy, Laguna vs. Municipality of Siniloan, Laguna

Both Municipality of Famy and Municipality of Siniloan, Laguna, are public corporations under Philippine law.
Historically, Famy was incorporated into Siniloan through Act No. 939 in 1903, then separated again in 1909 by Executive Order No. 72.
This led to a boundary dispute over the barangays Kapatalan and Liyang.

The Provincial Board of Laguna, on March 26, 1962, ruled that Siniloan had jurisdiction over the two barangays.
In 2001, an elementary school transferred to Barangay Kapatalan was considered under Famy’s jurisdiction; barangay officials were elected under Famy.
Siniloan’s Vice Mayor wrote to the Provincial Legal Officer to implement the 1962 Decision; Siniloan filed a Petition to Revive Judgment before the Sangguniang Panlalawigan.

Famy opposed Siniloan’s Petition by submitting a July 4, 1942 Provincial Board Decision granting Famy jurisdiction.
The Sangguniang Panlalawigan, in Resolution No. 498 (2005), upheld Famy’s jurisdiction, citing the absence of specified metes and bounds in the 1962 Decision and reduction in Famy’s population and land area if the barangays were transferred.
Siniloan’s Motion for Reconsideration was denied in Resolution No. 88 (2006).

Siniloan filed a Petition for Certiorari and Prohibition with prayer for a Temporary Restraining Order (TRO) and writ of preliminary injunction.
The Regional Trial Court (RTC) issued a TRO prohibiting both municipalities from exercising authority over the barangays.
On February 20, 2008, RTC issued a writ of preliminary injunction restraining implementation of the Sangguniang Panlalawigan Resolutions and enjoining Famy from interfering with Siniloan’s jurisdiction.
Famy’s Motion for Reconsideration was denied on August 1, 2008.

Famy filed a Petition for Certiorari before the Court of Appeals (CA) contesting the issuance of the writs, arguing they were improperly issued and constituted a resolution on the merits.
Siniloan contended the injunction was proper, citing ongoing criminal cases, voter registration, and tax payments in Siniloan’s favor.
The CA, in its August 22, 2011 Decision, affirmed the RTC’s issuance of preliminary injunction, rejecting Famy’s arguments and emphasizing the temporary nature of the injunction pending final resolution.
Famy’s Motion for Reconsideration was denied by CA on October 11, 2012.
Famy filed a Petition for Review on Certiorari with the Supreme Court, which gave due course and required comments and memoranda.

Petitioner (Famy) asserts the injunction was improperly issued incidental to a Petition for Prohibition, for which the writ itself is unavailing to prevent erroneous enforcement of judgments.
It claims certiorari is also improper as it cannot substitute a lost appeal.
Petitioner challenges the finality of the 1962 Provincial Board Decision, absence of proof of receipt, and prescriptive extinction of rights since 1972.
Petitioner argues government recognition of the contested barangays’ jurisdiction in its favor further negates Siniloan’s claim.

Respondent (Siniloan) maintains petitioner had remedies via appeal rather than certiorari or prohibition.
Asserts payment of taxes and voter registration in Siniloan evidence jurisdiction.
Charges petitioner’s case relies on a falsified 1942 decision and that Sangguniang Panlalawigan improperly overturned valid 1962 Decision.

Whether the Court of Appeals erred in affirming the Regional Trial Court's issuance of a writ of preliminary injunction in favor of Municipality of Siniloan.