It appears the tanker has escaped port, Zeidan order guys to fire but they wouldn't and maybe Islamists in the army deliberately didn't fire because they knew that letting Zeidan seem incompetent would bring down his regime and force him out of the country as it has done. The road ahead for Libya now looks very rocky indeed. What is clearly needed is a national unity government. For a quick overview of how things played out David Kirkpatrick's NYT piece is a good start.
Libya’s Prime Minister Ousted in Chaos Over Tanker