There's a very big IF. It's an allegation of potential links. India neither has a policy nor a history of assassinating plumbers. There are real terrorists involved in India's 9/11 holding speeches in Pakistan every Friday. If they weren't assassinated, I doubt a Canadian plumber would be.
It's been a few months since that guy was killed and still no evidence, no charges, no suspects. Nothing. Nada. Zilch.
That's what the leaks from Canada suggest. Although there had been some disinformation that he was a terrorist, there is visual evidence that he was a plumber.