If he wasn't born in Canada I'm sure they could "find" a lie somewhere on his immigration application.
Why is espionage not a reason for citizenship revocation.
The citizenship oath;
I swear (or affirm)
That I will be faithful
And bear true allegiance
To Her Majesty Queen Elizabeth the Second
Queen of Canada
Her Heirs and Successors
And that I will faithfully observe
The laws of Canada
Including the Constitution
Which recognizes and affirms
The Aboriginal and treaty rights of
First Nations, Inuit and Métis peoples
And fulfil my duties as a Canadian citizen.
By the wording of the oath they should be able to turf you for any broken laws.