G.R. No. 180291 - Government Service Insurance System vs. Villaviza

On May 27, 2005, respondents—GSIS employees—wore red shirts and assembled outside the GSIS Investigation Unit during office hours:

To demonstrate support for their union president, Mario Molina, and his chosen counsel, Albert Velasco, barred by a GSIS Hearing Officer under R.A. 6713.
To badmouth security guards and GSIS management, raise clenched fists, and allegedly disrupt work.

Petitioner Winston F. Garcia, GSIS President and GM, charged them with Grave Misconduct and/or Conduct Prejudicial to the Best Interest of the Service under GSIS’s own Rules of Procedure in Administrative Investigation (RPAI) and the CSC’s Omnibus Rules on Prohibited Concerted Mass Actions (CSC Res. 02-1316).

A May 31, 2005 memo by the GSIS Security Manager reported the incident; the GSIS Investigation Unit Manager required written explanations under oath within three days.
On June 6, 2005:

Six respondents (Duque, Echavez, Rubio, Gracia, Layco, Legarda) submitted unsworn letters denying any planned mass action, calling their presence “spontaneous support.”
Villaviza submitted a separate sworn explanation, citing her own scheduled pre-hearing.

Despite no answers being filed to the June 4, 2005 formal charges, GSIS issued June 29, 2005 decisions suspending each respondent for one year with accessory penalties.

On appeal, the CSC found only a violation of reasonable office rules, reduced penalty to reprimand, and deemed the assembly a protected exercise of freedom of expression.
The Court of Appeals (Aug 31, 2007) dismissed GSIS’s Rule 43 petition, upholding the CSC for lack of proof of work stoppage, substantial service disruption, or forceful demands.
Winston Garcia elevated the case to the Supreme Court via Rule 45 Petition for Review on Certiorari, raising both procedural and substantive issues.

May an administrative tribunal apply Rule 8, Section 11 of the Rules of Court on deemed admissions as a suppletory measure when respondents did not file answers?
Can an administrative tribunal admit and fully credit unnotarized letters not in the official case record without breaching due process?
Is a decision valid if its conclusions of law rest on allegations in documents absent from the case records?
Must petitioners prove substantial operational reduction due to the gathering to hold employees liable for conduct prejudicial under CSC Res. 02-1316?
Does the protest by about twenty employees inside office premises for over an hour fall within constitutional freedoms of expression and peaceful assembly?
Does the concerted abandonment of posts to hold this protest constitute only a violation of reasonable office rules and regulations?