A similar thing happend in Australia, when a man got off a boat on Sydney harbour wharf belonging to the Prime Ministers residence rather than a public one. He was dressed in camo style pants and had to climb a wall into the compound to get off the wharf.

Nothing much happened to him, as the Prime Minister was not there at the time.

http://www.smh.com.au/news/national/kirribillis-accidental-i...