Debbie McDonald came forward after a CBC News and Marketplace investigation looking at problems in local pharmacies, such as dispensing errors and staff failing to warn customers of potentially serious drug interactions.
McDonald says that if it wasn't for CBC's reporting, there could have been a medical tragedy in her family.
On Monday, she picked up what she thought was her son's acne prescription.
But when her son Kevin Richardson, 18, opened the pill container, he realized they weren't the same as usual.
On the alert after watching CBC's coverage, he Googled the pill's imprinted ID number and discovered that instead of the labelled Accutane, he had been given Accupril.
"He told me, 'Oh Mom, that's Accupril' and I said, Kevin, it can't be Accupril'" McDonald said.
If Richardson had taken the medication, it could have been potentially catastrophic, because he's a novice pilot just starting to fly solo and he could have passed out alone at the controls.
"It could have been a tragic ending for something that if there are checks and balances in place wouldn't have happened," McDonald said.
When the concerned mom contacted the Surrey London Drugs that made the mistake, she said, the pharmacist was defensive until the manager got involved.
"He's very apologetic and very concerned that something went amiss in his pharmacy," she said.
London Drugs issued a statement saying it was "extremely disappointed this error occurred."
"[Our] preliminary review indicates that this is due to human error," the statement said. "We have apologized to the patient and the investigation continues."
Read London Drug's statement