Sources close to Brigadier General Manaf Tlas, who met him days before he deserted, told the BBC he was very angry about what was happening in Syria and accused the regime of "taking the country to Hell".
"If I were him, I would have done an [former Turkish leader and political reformer Kamal] Ataturk or resigned the second month the uprising began," the sources quoted him saying of Bashar al-Assad, before he left for Turkey.
A commander in the elite Republican Guard, Gen Tlas is the highest ranking official - and the first from President Assad's inner circle - to desert since the uprising began in March 2011.
Gen Tlas had been under partial house arrest since May 2011 because he opposed the regime's response to the uprising.
He was the first government official to meet the opposition, back in March 2011, seeking to open a dialogue and find a political solution to the crisis.
He was also involved in reconciliation efforts in rural Damascus - mainly in Douma and Daraya and Tal - as well as in Homs and his home town Rastan.
Brig Gen Tlas met residents of several towns and helped obtain the release of many of their prisoners, even taking families from Douma to meet President Assad, who promised them a peaceful solution.
Brigadier in elite Republican Guard
Member of Syria's most powerful Sunni family
Son of former defence minister
Member of the ruling Baath Party's Central Committee
Close friend of Bashar al-Assad
Profile: Manaf Tlas
Bashar al-Assad's inner circle
But Rastan was the turning-point for Manaf Tlas.
In May 2011, power and mobile networks were cut off in Rastan in preparation for an attack on the city by the official forces. Manaf Tlas ordered the services to be restored and promised the protesters they had the right to demonstrate peacefully.
Celebrating this, protesters chanted his name, which was enough to anger Maher al-Assad, Bashar's brother and head of the Republican Guard, who ordered Manaf Tlas to stay at home.
Gen Tlas continued going to his base but no longer with any power to issue orders.
Hours after his desertion was announced, his house was ransacked by a mob, under the watch of the army, eyewitnesses said.
The BBC has spoken to members of Gen Tlas' family, but they refused to comment.
His wife, Thala Khair, and other family members, are in Paris.
Role in the opposition?
Many people within the opposition see Manaf Tlas as someone who has not been involved in bloodshed and believe he could play an important role in a transitional phase in rebuilding the military establishment.
Members of the Free Syrian Army (FSA) who defected from the military, are said to hold hopes for Gen Tlas as a reputed army figure.
Manaf Tlas was a friend of President Assad and the son of former Defence Minister Mustafa Tlas.
During the last 10 years he was acting on instructions from Bashar Assad to build good ties with the intellectual society of Syria.
His brother Firas Tlas, a businessman, has been accused of corruption and of benefiting from the regime.
But many activists say he has been largely involved in the uprising, providing humanitarian aid to the affected families.
Firas Tlas had strong links to the opposition and left the country a few months ago, pledging his support for the rebellion. He is now living in Paris.