Is the defection of Syria's Prime Minister the final blow for Assad?

The BBC have reported that Syrian Prime Minister Riad Hijab has defected to Jordan.

Unconfirmed reports suggested that two other cabinet ministers had also deserted and there were claims that a third, Finance Minister Mohammad Jalilati, had been arrested while trying to flee.

The article goes on to say that:

Last month, Syria's ambassador to Iraq, Nawaf Fares, deserted to the opposition. Like the former prime minister, he was also from Deir al-Zour. Brig Gen Manaf Tlas, who was considered close to President Assad, also defected in July.
Thirty other generals have crossed the border into Turkey and Turkish news agency Anatolia reported on Monday that another general had fled with five high-ranking officers and more than 30 soldiers.

Could the loss of such a high ranking member of his government in so public a fashion be enough to convince Assad that it's time to admit defeat or will it cause a further escalation in the violence that is tearing Syria apart?