From the Transport Canada aviation medical standards:
3.3 The applicant shall have no established medical history or clinical diagnosis which, according to accredited medical conclusion, would render the applicant unable to exercise safely the privileges of the permit or licence applied for or held, as follows:.....
(b) alcohol or chemical dependence or abuse;.......
That seems pretty clear to me. Agreed that alcoholism is a disease, but it's a disqualifying disease for a pilot.
Poor bloke has his demons to fight, some support from his employers would be the first step...
He should fight his demons away from piloting duties. I struggle to understand why his employer should support him, when he was intent upon putting his employers and their clients at huge risk. Perhaps they would support a pilot who declines flying duty to the chief pilot/company doctor with a conversation which begins "I have a problem..."
By presenting yourself to act in the capacity of pilot, you are declaring that you are medically fit. He misrepresented the facts.