I'm no fan of stories like this, but from the article let's get a couple of facts straight....
1. He is a Canadian citizen.
2. "The Pakistanis are ready to let him go. It looks like they don't have anything against him. They won't object to his departure."
So, until his citizenship is revoked he is entitled to return to the country of which he is a citizen, particularly if "they don't have anything against him". Presumably, our Government doesn't have anything on him either and even if they did, they would not be allowed to deny him entry to Canada (although he might immediately be charged and be locked away).