The evidence this is him is circumstantial: the timing - around 2003 - fits with reports that after the death of his parents in 1998 and 2001 he became disaffected with the military and tried to leave. He even went so far as to hire a lawyer. And Nidal Hasan is not as common a name as you might think, as per Facebook and Google.
The evidence against: the petition is Canadian, and there is no record of him having lived in Canada at any time.
Fly my pretties; if you think this is crap, or indeed can help prove it, then comment or email.