All in all, this Khobragade episode will turn in to a Business School & International Relations course on how NOT to conduct diplomacy and how NOT to shoot yourself in the foot and how the other side can rally and beat the bejesus out of you.
Firstly, the US did the "traditional" foreign policy approach. Take prisoners, browbeat the other guy with power dynamics and try to "manage" this with a servile "traditional" media that is fettered and amenable to control , with the "strategic" goal being to secure an admission of guilt and to push a message "of war against slavery/human trafficking" and paint your side as being purer than the driven snow and driving the agenda.
The scene was set with the maid bolting to the US govt sponsored "Safe Whatever" run by a gaggle of activists led by a Harvard MBA (Haahvud YumBeeYea) and access to govt and media and inner circles. The idea was to prosecute, get into the press, present the maid as a poor oppressed by a rather meek foreign govt that is also conveniently third world, but does have an open system that allows you this kind of leeway, while most others like China would kick you out pronto, in short a soft target, and then you come across as the knight in shining armor and US and Obama can make all the hoopla and claim glory in the "Fight against modern slavery / trafficking" thing. The arrest motion was put into play after covering your bases by getting the rest of the family out of the other guy's physical control.
Trouble is the other side didn't react as you expected . They went public, including the demeaning circumstances of the arrest , and the entire thing blew up. Immediately the other side normally fractious got united, you were facing serious damage to larger interests, faced immediate retaliatory action where there were tangible losses to you, but couldn't climb down without serious loss of face and a bruised black eye. So you try to get a an admission of guilt in a plea. But the other side was much clever than you. They did something which no one had done when you arrested before for exactly same reasons (for eg, the Ambassador of Mauritius or something) and didn't play by your play book.
They steadfastly refused to accept your jurisdiction and moved it out to a full immunity by a transfer to UN, which you had not gamed before you made the move ! This made the case even more complex for you because
every OTHER country now knows what to do when one of their diplomats face an arrest for any reason.. transfer them to the UN and you can do zilch about it. You already have lost the war here, now all that remains is to look for an orderly retreat and not face a full rout. So you, expel the person you targeted and tarnished, knowing that the other side will do the same , and you can call quits and both sides will call a draw and claim half victories.
This is where the social media revolution blew up your entire overall strategy to smithereens. You never gamed the fact that there is something called a media that you cant control, a media that can drive YOU to the ground. Once the other side got back their guy , rather than the dying down, the entire thing blew up in your face. The non govt actors from the other side , a diffuse, nebulous, unknown entity that you cant even reach out to unleashed a barrage that you have no answer to. Exploiting the power of this new media , Anmol and BRF launched a broadside which ripped off the cover you were hiding under and held up a mirror that was simply too ugly to be ignored or swept under the carpet. The counter attack hit all the weak spots, and everyone including the servile traditional media have to come on board.
Result, what started as an offensive with all the cards in your favor on a divided , unprepared opponent, turned miraculously into a total disaster and a rout.
Congratulations USA! Well done. Every other country has learned what to do to you now and how to stand up to your bullying. Very apt, that you have appointed a person " Who self discharged a small pistol on his legs"

to a position of authority. It seems like he has got you guys to do an encore, as he is habitually wont to do , ie Shoot yourselves in the leg!