Re: Here's a question
Nope. There is no diplomatic protection to give. if he's outside the embassy, he's fair game. In or out of a diplomatic bag.
The police are allowed to arrest diplomats, they just can't charge them without permission of their own government. I doubt you're allowed to hold them for long either, and you have to contact their embassy once you've got them.
As for the ABC thing, the Guardian yesterday say that Ecuador tried it. Some journo found his name on their equivalent of the electoral rolls - meaning he's been given citizenship, if true. And they recently applied to the UK government for a diplomatic visa. Which was refused.