Hardly evidence though is it, Keyplus? The article you link to is written by a kashmiri activist based in Nottingham, UK, posted in the editorials and letters sections of an obscure canadian? newspaper or online news outlet. So the source and the media outlet do little to add credibility to the tale.
When you look at this story in a little more detail and seek out a few more sources, it turns out to be rather more mundane and far less dramatic. A local government official is claiming that a police officer made these claims to him by means of a letter!
http://timesofindia.indiatimes.com/india/Satish-Chandra-Verma-may-have-to-explain-26/11-remark/articleshow/21093685.cms
So - no evidence that the police officer actually made the allegation. No evidence to support the actual allegatiob itself. No supporting background details - as far as i can tell, this Verma chappie has had no personal experience of working in the intelligence services.
The analogy is that a senior police officer in, say, Tampa, Florida, is alleged by an ex government official to have claimed that 9/11 was an inside job by the CIA.
What can be asserted without evidence can be dismissed without evidence.This story may fit into your own bias, Keyplus, but at the moment on the facts as presented does nothing to change the settled view that the Mumbai terrorist attack was inspired by and orchestrated by elements within ISI....
http://en.wikipedia.org/wiki/2008_Mumbai_attacks