Daily Tribune editorial relates what happened succinctly (if exasperatedly):
Section 2. The President, the Vice-President, the Members of the Supreme Court, the Members of the Constitutional Commissions, and the Ombudsman may be removed from office on impeachment for, and conviction of, culpable violation of the Constitution, treason, bribery, graft and corruption, other high crimes, or betrayal of public trust. All other public officers and employees may be removed from office as provided by law, but not by impeachment.
Section 3. (1) The House of Representatives shall have the exclusive power to initiate all cases of impeachment.
(2) A verified complaint for impeachment may be filed by any Member of the House of Representatives or by any citizen upon a resolution or endorsement by any Member thereof, which shall be included in the Order of Business within ten session days, and referred to the proper Committee within three session days thereafter. The Committee, after hearing, and by a majority vote of all its Members, shall submit its report to the House within sixty session days from such referral, together with the corresponding resolution. The resolution shall be calendared for consideration by the House within ten session days from receipt thereof.
(3) A vote of at least one-third of all the Members of the House shall be necessary either to affirm a favorable resolution with the Articles of Impeachment of the Committee, or override its contrary resolution. The vote of each Member shall be recorded.
(4) In case the verified complaint or resolution of impeachment is filed by at least one-third of all the Members of the House, the same shall constitute the Articles of Impeachment, and trial by the Senate shall forthwith proceed.
(5) No impeachment proceedings shall be initiated against the same official more than once within a period of one year.
(6) The Senate shall have the sole power to try and decide all cases of impeachment. When sitting for that purpose, the Senators shall be on oath or affirmation. When the President of the Philippines is on trial, the Chief Justice of the Supreme Court shall preside, but shall not vote. No person shall be convicted without the concurrence of two-thirds of all the Members of the Senate.
(7) Judgment in cases of impeachment shall not extend further than removal from office and disqualification to hold any office under the Republic of the Philippines, but the party convicted shall nevertheless be liable and subject to prosecution, trial, and punishment, according to law.
(8) The Congress shall promulgate its rules on impeachment to effectively carry out the purpose of this section.
Davide and a couple of other justices were facing two impeachment complaints, the first of which was sat upon by the House, while the second one, which had the required signatories, focused solely on Davide in the matter of the misuse of the judiciary development fund.Ever since then, I've come to the conclusion that what has really happened here is that the Supreme Court USURPED the House of Representatives exclusive power to impeach Constitutional Officers (Section 3) the the Senate's sole power to try and decide all cases of impeachment (Section 6) and the Congress power to make the rules for such process. (Section 8).
To evade an impeachment trial and to save the prostituted hide of Davide, the high court’s interpretation of Article XI, Section 3 (5) which states that no impeachment proceedings shall be initiated against the same official more than once a year, was that the proceedings meant the filing of only one complaint a year, thus opening wide the doors of instant immunization of the impeachable officers through the filing of a yearly bogus complaint.
One must not forget either that the prostituted House of Representatives helped to strengthen this Davide Court ruling, by ensuring that the bogus complaint is accepted, while amended complaints that have substance are immediately killed, without benefit of the presentation of evidence.
This unconstitutional ruling by the high court has been used to the hilt by Gloria Arroyo and her allies in the House, to immunize herself from impeachment proceedings, then, now and up till her term ends — and by the simple expedient of getting someone to file a bogus impeachment complaint yearly which will then be endorsed by one of her congressional allies.
The clear intent of the Constitution is to shield Constitutional officers from the nuisance of multiple impeachment suits, but not the House and Senate from properly exercising their EXCLUSIVE and SOLE powers to impeach, try, and adjudge all cases of impeachment.
Related Philippine Commentary:
What Is Fair Has Just Priority Over What Is Good
Our Bantay Salakay Supreme Court and the Separation of Powers
Update: The Political Junkie looks at this issue in greater detail. (Hat tip to John)