I more I read on this story, the more my suspicion grows that the West has cut a deal with Gadaffi and that continued talk of no fly zones and support for the rebels is simply hubris.
Clearly the West has Gadaffi by the short and curlies and can demand significant concessions from him, in order to buy his survival. By contrast, they would have no such leverage with the rebels, who; if victorious, would hold a moral authority that would make them untouchable and able to renegotiate upwards any Oil contract agreed by the Gadaffi regime, with total impunity.
The SAS and their "diplomat" were captured several hundred miles east of any known Government forces and in the heart of rebel controlled territory. This is highly suggestive that they were performing reconnaissance of, rather than for, the rebels. The Rebels reaction to finding them, is highly suggestive that they took a very similar view, otherwise the thing would have been resolved quickly and never make the public arena. There are after all, only a limited number of likely beneficiaries of such intelligence.
Leaders may not like Gadaffi, but he is reliable from an Oil production perspective, as with up to 100000 international oil workers and dozens of companies operating in Libya until the revolt, the country never made the news for "production problems".
I guess also that the rebels are too much of an unknown, composed of largely hostile nationalists as well as Islamists , all of a less than concise cohesion.
Better then the devil you know, especially when held by such advantage!