Practicality/legality of a Julian Assange helicopter extraction.

Or Ecuador could just give him a diplomatic passport and be done with it.
Most likely, they will give him an Ecuadorian passport, wait until the crowds are gone, take him in a diplomatic car to airport and put him on a diplomatic transport.
TADA

problem solved.
refueling? whatever. Airports refuel diplomatic transports all the time without wasting time searching the planes.

England is saber rattling that they would actually invade a country in order to extradite someone to a 3rd country? LOL. not going to happen. The diplomatic uproar would create way too much international upset.

Most countries REALLY dont want their embassies being attacked.

/why didnt osama just hide out at the Saudi embassy in Pakistan?