Christopher Sitarz, 34, was arrested in February with three times the legal limit of alcohol in his bloodstream.
He was driving the wrong way through heavy traffic in Toronto's downtown entertainment district, and exhibited "a dead stare," bloodshot eyes and unsteadiness at the scene, the Toronto Star reported.
On Wednesday, he was acquitted, with the judge accepting Sitarz's argument that someone may have spiked his drink when he went out for a smoke earlier that night.
"It is reasonably plausible that a substance was slipped into his drink which so affected his cognitive abilities that his subsequent alcohol consumption was no longer voluntary," provincial court Justice Kathleen Caldwell wrote in her ruling.
Sitarz testified that he had been attending a "Fast Life" dating event at a downtown bar and was observing the "one drink per hour" rule.
He remembered ordering one or two vodka Red Bulls, then groggily talking to a woman. He claimed her remembered virtually nothing after that.
The next day, he went to a hospital emergency room to ask if he could have been drugged.
Caldwell found that Sitarz raised reasonable doubt that his impairment was completely voluntary and subsequently acquitted him of the impaired-driving charge.
"Watch your drinks. That's all I can say," Sitarz told the Toronto Star after Wednesday's verdict.
While most reported drugged-at-the-bar cases involve female victims, Sitarz isn't alone in his claim.
Last July, a British woman spiked a Royal Air Force (RAF) airman's vodka and Red Bull with half a gram of cocaine, causing him to test positive in a random drug test at work the next day. Amanda Williams turned herself in, admitting to administering a poison or noxious substance with intent. This summer, she was given a suspended 12-month jail sentence. The airman, Mark Boyle, continues to serve with the RAF.
In Ireland, rugby player Brandon Cowhig insisted his out-of-character outburst at a nightclub was the result of a spiked drink.
Defence lawyer Stephen O'Mahony said Cowhig had no recollection of the incident and believed his drink must have been spiked as he had a "total blackout," Herald.ie reported. A judge still fined the young man €200 ($254 CAD) for the damage his behaviour had caused.