Diversion is a serious thing...
But in our litigation-prone society, if you've got a guy who is non-cooperative and obviously drunk, he's a liability on the aircraft. I'd make the same decision and booted his ass off the aircraft and into the waiting hands of the RCMP. Once the aircraft is in the air - the Captain legally has the authority of a peace officer...and although I'd hate to exercise that option when you've got a boatload full of pax and one beligerent asshole, out they go.
Just imagine the sh#tstorm if this prick continued getting loaded...and an EVAC was necessary. He's then a liability that the crew knew about, and could impede himself and others from making it out OK. I'm all for beers on board, but people need to know what is acceptable, and what isn't. This Captain just helped illuminate to the flying public what isn't cool.
I saw a similar situation go down on a flight to YVR on WJ. A guy and girl in front of me were completely loaded (and arrived that way at 7AM...losers) on their way to the Bahamas for a vacation (they insisted on screaming this throughout the flight). The FA warned them multiple times to settle down or she would have no choice but to get the Captain involved. They didn't heed the warning.
They didn't make their connection to the Bahamas that day

. Again, people need to understand what is acceptable and what isn't - and the possible consequences...