The URL structure was indeed changed
I looked through the archives of your blog and found that the URL of that post is really http://madhurchadha.com/2012/03/14/gurgaon-8-pm-rape not http://madhurchadha.com/2012/03/gurgaon-8-pm-rape
If you test via https://developers.facebook.com/docs/plugins/like-button/ , you will see that the page still has 5,659 Likes and 116 Tweets ( http://urls.api.twitter.com/1/urls/count.json?url=http://madhurchadha.com/2012/03/14/gurgaon-8-pm-rape )
A workaround would be to change the Share URLs to the Old Post URLs but keep the Post on the current URL (As I have checked the old URL does a 301 redirect to the New URL )
Other thing people recommend is pointing the Open Graph og:url Meta tag to the old Post URL (But this has some problems as well , if all your posts weren't using the Old URL Structure , then this might lead to problems in counts. Also currently your post don't have any Open Graph Meta tags other than og:image )
You will have to change the URL structure again or Likes will not appear (Once information about a URL is created in the FB database , that can't be transferred to another URL) But be careful as your posts are now a mixture of ones using the URL those that were migrated from the Old URL structure and ones which were created on the New URL structure .
So I suggest changing the URL structure of the ones that were migrated from the old URL Structure to their original URL. This will introduce non-uniformity in the URL structure but is the only sure way to get the Share counts back easily
Hope this helps