Ping, fish, you may be interested in this, another diplomatic screw up.
Thank you, Patriot!
In fact there are really few legal grounds to detain a diplomat(being captured red-handed on a murder scene and some very similar situations), and none to arrest one without certain authorisation by a nation or recognized international body which is represented by said person.
Underpaying nunny is actually a ridiculous charge to arrest any person, let alone a diplomat from a friendly nation.
NYC might be an absolute police state, I don’t think a case of underpaying a nunny may pass beyond a civil dispute even in Red China.