How to leave an embassy
I have a solution to the problem.
1 the Ecuadorians tell St. Julie the Ass that they have a way of getting him out of the embassy without being arrested by HM Gov. It involves the co-operation of the Brazilians. Basically, the Brazilian navy, as part of the first shakedown cruise of their new fleet flagship, PHM Atlântico nee HMS Ocean, will send a helicopter to winch him up from the balcony and fly him to the assault ship. He will then have a nice sea cruise back to Brazil and will be turned loose in Rio, hopefully in time for Carnival next year. I'm sure that St. Julie would particularly like the thought of using an ex-British ship to evade getting his collar felt by PC Plod.
2 at the appointed time a SH-70 Seahawk helo in Brazilian colours arrives over the embassy and St. Julie is winched up, to be greeted in Portuguese. The helo flies on out towards the Channel, where it sets down on a large amphibious assault ship flying the Brazilian naval jack.
3 as soon as St. Julie sets foot on deck, he is arrested by some US Marines, the Brazilian jack goes down and the US Navy's jack goes up, and a large decal on the SH-70 is removed to reveal US Navy markings.
4 St. Julie enjoys a nice sea cruise to the Caribbean. After a stay in south eastern Cuba, he is handed back to HM Gov, and after a stay in the finest gray-bar hotel in Britain, to the Swedes, who can now use him for his finest purpose: polar bear bait.
Ecuador and Brazil get some nice presents for their trouble. The poor bears might get indigestion.