Can they not put him in a helicopter with a diplomatic courier or minor embassy functionary and fly him out to a boat in international waters?
(Edit: I see now that was already discussed below. nm.)
That asked, I tend to agree that the most likely case is that Ecuador is only involved because they want unrelated concessions from the UK and will likely turn him over after some brief negotiations.
That asked, I tend to agree that the most likely case is that Ecuador is only involved because they want unrelated concessions from the UK and will likely turn him over after some brief negotiations.