Could you provide a link to that interview? I think some context would be helpful in answering your question (not to mention that I'm unaware if this interview).

Edited excerpt from a paper I wrote a couple years ago:

In the first election for Congress, Boris Yeltsin was elected from Moscow with 90% of the vote. Yeltsin had long criticized Gorbachev for taking the reforms too slowly (Tracey 74). By November 1990, Gorbachev's popularity was only at 20% approval, and he was forced to cancel the 500 Days plan, which had included drastic economic reforms (Tracey 75). Gorbachev sent troops to quell pro-Yeltsin rallies, but public opinion had swayed too far. On June 12 1991, Yeltsin won the presidency of Russia, putting him directly at odds with Gorbachev (Tracey 75-76).

...Gorbachev had intended for the democratization reforms to breathe new life into socialism in Eastern Europe and fully intended to extend the life of communism (Sebestyen 136), but quite to opposite happened: Poland, Hungary, Czechoslovakia, Bulgaria, Romania, Latvia, Lithuania and Estonia all shed their communist leadership, and the destruction of the Berlin Wall led to the reunification of Germany, which hurt the Soviet economy in terms of lost industry, manpower and resources. In response to this, hardcore communists led by KGB chairman Vladimir Kryuchkov staged a failed coup d'état against the Gorbachev government, which is commonly seen as another of the factors that contributed to the fall of the Soviet Union. While Gorbachev was in vacation in the Crimea, the rebels placed him under house arrest, but it was quickly quelled by Yeltsin and his supporters. However, as Gorbachev says himself in his book The August Coup:

It is true that the conspirators did not succeed in carrying through to the end their criminal plan to hurl the Army against the population. The Army turned out to be with the people. But nevertheless it turned out to be possible to bring out on to the streets a huge number of troops, tanks and other armored equipment without any agreement on the part of the country's supreme legislative body. This is an obvious fact, and it means that there is something wrong in our machinery of government (Gorbachev 42-43).

/excerpt finish

So I think this quote addresses your question somewhat; as it seems fairly possible for soviet military elements to be deployed without Politburo authorization, which could potentially be used for a "rebellion" side in a civil war.

Gorbachev, Mikhail Sergeevich. The August coup: the truth and the lessons. New York, NY: HarperCollins Publishers, 1991. Print

Tracey, Patrick Austin. Political reform leaders in Eastern Europe and the former Soviet Union. New York, N.Y.: Facts on File, 1997. Print.

Sebestyen, Victor. Revolution 1989: the fall of the Soviet empire. London: Phoenix, 2010. Print.

From what I understand, it was much less about Gorbachev worrying about a civil war, but more about him really not having a lot of influence on anyone after being freed from his dacha in Crimea where he was under house arrest.

To give a little bit more of a context, I won't describe the entirety of the Perestroika/Glasnost era policies, but Gorbachev came in as a serious reformist after Brezhnev's all around stagnant term while in power. By the time it was August 1991, many landmarks of the Eastern Bloc had fallen, and Gorbachev's reforms were at the point where he was actively hoping to salvage the union by turning it into a Swedish model social democracy. Most importantly, around March 1991 Gorbachev announced his desires to reform the Soviet Union into a completely voluntary federation of states, and the Russian Federation was founded with Boris Yeltsin (A pro-market economy leader who was popular with the masses) as the first president, and a voluntary member of the Soviet Union led by Gorbachev. This arrangement was obviously a temporary fix and very shaky as it looked, but it was at that time the "hardliners" in the army (basically the people in higher positions in the army who wanted to restore Soviet socialism to Brezhnev era policies (which were stricter compared to even Khrushchev's Thaw era that came before him)) declared a coup. The aim is to oust Gorbachev, install his vice-president Gennady Yaneyev as the new one and pretty much re-establish the old Soviet Union. Gorbachev is in his dacha in Crimea -- a dacha is basically a summer house and a staple of Russian culture--, Yeltsin is at the parliament. The coup leaders shut down the Crimean airport, and the navy shuts down the harbor where Gorbachev's dacha is. At the same time in Moscow, Yaneyev declares himself the new president and says that Gorbachev is having health problems and voluntarily resigning. In these circumstances, Gorbachev is practically under house arrest.

Tanks arrive at the parliament to arrest Yeltsin, but he refuses to give in, climbs on a tank and gives a speech where he declares himself the rightful leader of the federation and calls for a general strike.^^1

The thing is, these hardliners really don't have much support beyond their military prowess, so as long as Yeltsin's voice is heard many are hesitant to actually take care of him. I believe some forces turn against the coup organizers and on August 20, the second day of the attempted coup, around 100,000 gather in front of the White House in Moscow to protest the coup, with Yeltsin giving a speech and pretty much solidifying himself as the person to be in power if the coup is successfully stopped. On the 21st, at that point every other major Soviet republic (Ukraine, Kazakhstan) have declared their support for Yeltsin, and the army too. Tanks fail to enter the parliament square, and as everyone starts backing Yeltsin the coup leaders flee Moscow.

Gorbachev is freed and returns to Moscow, but by that time Yeltsin is the center of attention, the savior against the coup, and Gorbachev's influence has basically vanished. Gorbachev resigned as the general secretary a few days later, fires most of the anti-Yeltsin members of the Politburo, and remains as a president mostly in name until the Union is officially dissolved in December after specifically Ukraine decided to vote against staying in the union in their referendum.

So it was less of a case of starting a civil war, but basically there was nobody left who was a staunch Gorbachev supporter at that point. Keep in mind that Gorbachev is pretty unpopular for the very visible decay of the USSR from the "other super power" into a shell of itself, and his anti-populist policies such as his war on alcoholism -- how unpopular that action was really can't be understated. The pro-hardliner crowd lost when the coup failed, and people were fully behind Yeltsin who was now the person to lead Russia into the future. If he refused to do so, a much likelier outcome would be Yeltsin voting to dismiss Gorbachev from power, granting independence to all the federation states and not drawing great backlash from any crowd apart from the effect of the removal of the Soviet name -- although this is of course speculation.

Sources:

^^1: http://soviethistory.msu.edu/1991-2/the-august-coup/the-august-coup-texts/eltsins-defiance/

In addition checked my copy of Suny's The Soviet Experiment, a great secondary source, for some facts just in case.

As a follow up: is there any indication that process of dissolution would slow down would he refuse to do so? as it happened in the last days of Union, was he in position not to do this (for example order not to pass control over nuclear weapons to RSFSR authorities)?

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