Carlos Mendoza also told The Associated Press in an interview that he never had designs on power himself, saying, in effect, he tricked the other two men with whom he briefly formed a revolutionary junta on Friday.
And he urged compassionate treatment for the junior officers who he said forced him into demanding Mahuad's resignation by joining Indians earlier that day in seizing key government buildings.
Many analysts believe Mendoza, who stepped down as military commander and defense minister when he dissolved the junta early Saturday, had determined he didn't have enough support in the armed forces to seize power.
Mendoza acknowledged his awareness days before the coup that Col. Lucio Gutierrez, a soldier attached to military headquarters who led the uprising, was conspiring against Mahuad.
But as Mendoza told it, he only decided to ally himself with the insurrection when it became clear Indians and renegade officers would otherwise try to storm the presidential palace - and the palace guard would respond with gunfire.
In an hour-long interview Sunday night in a private Quito home, the career soldier described the Friday palace meeting at which the high command split with Mahuad.
"When the situation became complicated, we told the president, 'You have to decide. You decide so there isn't trouble in the country and try to pacify things,'" Mendoza said.
"He banged the table. He lost his composure. And I told him, 'You can't pound on the table. You are here facing the military command. You are wrong.'"
It was midday and thousands of Indian protesters, joined by 80 junior officers, were already in control of the Congress and Supreme Court.
Seeing no other solution, Mendoza and his entourage marched out of the room and he issued a public appeal for Mahuad to resign.
"I have not been a disloyal man," Mendoza insisted.
But Mahuad had vacillated on too many issues, he said, from failing to combat rampant corruption to turning a deaf ear to the Indians' petitions to cutting the military budget, impoverishing his soldiers.
Mahuad simply lacked leadership, Mendoza said.
"I think he was an intelligent man, but he was indecisive at the moment of truth," said Mendoza, who became army commander when Mahuad took office in August 1998 and armed forces commander in November.
Two weeks ago, Mahuad named him defense minister.
Although Mendoza said he had no disagreements with Mahuad until Friday, he described the deposed president as aloof, out of touch with society and the military. "If I spoke with Dr. Mahuad five or six times, that was a lot," he said.
Ecuador's grave economic crisis - its 12 million people have seen their purchasing power plummet 300 percent in the past year due to soaring inflation and cripling devaluation - has created deep discontent among the country's 35,000 professional soldiers.
Enlisted men now earn the equivalent of $40 a month, colonels earn $250, while Mendoza earned $640.
Budget cuts have also forced the military to mothball some of its equipment, to say nothing of modernizing, said Mendoza.
Mahuad was widely condemned for bailing out 18 failed banks last year at a cost of $1.2 billion after the bankers stole the funds and fled abroad.
In what many considered a last-ditch rescue attempt, Mahuad announced Jan. 9 that Ecuador would abandon the sucre and become the first South American nation to embrace the dollar. The new president, Gustavo Noboa, has vowed to proceed with the plan.
Mendoza said the estimated 200 officers who participated in Friday's uprising would have to be tried for their transgressions but urged that sympathy be shown.
Noboa, who as vice president was constitutionally next in line when he assumed the presidency Saturday, has praised Mendoza's sacrifice.
"If I had had ambition, I would have stayed that night and taken advantage of the situation," Mendoza said of his decision to abandon his revolutionary junta partners - Indian leader Antonio Vargas and ex-Supreme Court Justice Carlos Solorzano.
Mendoza departed for military headquarters early Saturday, convened the high command and put an end to the coup. Without offering specifics, he acknowledged receiving telephone calls during the crisis from unnamed U.S. diplomats who urged him to restore civilian rule.
Vargas has publicly accused Mendoza of betrayal, but the military man said it was clear to him who the real traitors were.
"For me, the greatest treason would have been to divide the armed forces," he said.
A cavalry school graduate, Mendoza's 38-year military career included stints as a helicopter and fixed-wing aircraft pilot and schooling in the United States at Lakeland Air Force Base in Florida and Fort Rucker, Ala.
He said he would not return to the military but could see himself running a business.