I am not sure where the figure of $4,500 is coming from. $9.50/h * 60 hours * 4 weeks is $2,280/month. I am using 60 hours a week rather then 40, considering that servants probably work longer hours. The US law was clearly broken in this case because the servant was not part of the diplomatic staff and was brought to this country under false pretenses.
However, to all of you who are now screaming for equality, please remember that in India the solution of "if you can't afford to pay your servant well, you should not have one" is NOT a solution. The simple fact is, there are a lot of middle (and lower middle) class people in India who can not (or will not) pay their servants more than they already do. If the laws pass that require servants to be paid more, some servants will be lucky enough to make more money as a result, others will starve to death because they will go from making $64/month to nothing at all. Unless you first address the issue of people willing to work for such a low wage, because they have no other options, you will only cause further misery.