Rivero disagrees with gun-use for self-defence

What exactly happened?

A US consulate employee (Davis) shot dead two Pakistanis on a motorcycle from his car last Thursday in a crowded part of the city. A third man was later killed in a hit and run when a US consulate car, reportedly sped down the wrong side of the road on its way to aid the American. The US employee reportedly told Pakistan police that he was acting in self-defense and that the men, who were armed, had tried to rob him after taking out money from an ATM.

The US consulate employee remains in Pakistani custody. He is charged with two counts of murder and of possessing an illegal firearm.
SOURCE

If this was an American in America, Rivero would be outraged. How does he know it wasn't self-defence? He doesn't - he can't know it.

And look how he treats American "demands" for the return of a national they say has diplomatic immunity? Rivero seems to suggest such demands are insensitive because of the volatile atmosphere in Pakistan. Whereas when Israel boarded the recalcitrant Mavi Mamara and an American citizen was killed, Rivero wanted the US to declare war on Israel. Domestic Israeli opinion and possible unrest has never featured in Rivero's discourse, so why should Pakistan's?

It isn't difficult to see Rivero's game. Rivero will abandon principle for realpolitic whenever it suits his agenda - but when his enemies pursue realpolitic rather than principle he condemns it for lack of principle - and when his enemies pursue principle regardless of the politics he condemns them for their lack of realpolitic.

In this instance, Rivero disposes with principle and suggests US is ham-fisted in demanding Davis' release and thereby provoking public animosity. What he omits to say is that

"U.S. officials....believe Davis is being held despite his diplomatic immunity because of fears that releasing him might cause domestic unrest."
SOURCE

So, according to Rivero the US should abandon international convention because of fears of unrest, but never considers that Pakistan aren't releasing him because of the same fear of unrest. [Did Israeli concern over the Mami Marmara sway him any? No.]

Diplomatic immunity is reprehensible perhaps, but it is what it is. Domestic unrest in Pakistan is no reason to abandon international treaty nor is it a reason to abandon a citizen-servant of the American state (one with Diplomatic Immunity, a status protected under international law and treaty).