I did a search on Yahoo. There is a Veterinary Board of Conduct in the US. I would do a search for Canada. They have to follow guidelines just like US Vets do.
This is disgusting.....you don't even want to hear how I would have handled it......she would have been missing her ear drum......not physical violence.....just my screaming in her d--m ear drum......
I would definately find who owns the practice....she may not.....and then file a complaint with owner, and the location where this service was being provided....and write a letter to the editor.....I would not stop until she was severely reprimanded.