I expect the attack on any Gadaffi forces advancing is being justified on the grounds that they are currently bound to attack civilians also. If the reports (from a doctor) from Misrata are correct, Gadaffi has snipers surrounding a hospital shooting anyone going in or out. Shades of Bosnia. Gadaffi is not being as cynically intelligent about this as Saddam was, so bombing anything (general ammo dumps, rather than strictly AD ammo dumps for example) is OK.
Then there's always the 'Belgrano' argument, that anything retreating could turn round...
Gadaffi is making it easy to convince even the most dove-ish that continued action is required.
Syria next! At least we'll be able to operate from AKR. Tip-top, number 1 base!