As it would be illegal for a pet shop to sell these fish in BC, I would have to assume that this fish was caught by angling or in a net and then taken home and placed into that aquarium. This person has effectively broken at least one angling law/regulation. IE. From page nine of the '06-'07 Synopsis, not certain on what page of the current one. "It is unlawful to... Have any live fish in your possession in the wild, or move any live fish or live aquatic invertebrates around the province or transport them into any waters of BC. Do not keep angled fish alive in a "livewell" or other device, or on stringers, and never use live fish as bait (neither I, nor the regulation, are referring to the use of the goldfish in this particular instance) or release your aquarium fish to the wild. "High-grading" is illegal."
I would be further tempted to believe that, having likely known that he/she has broken this regulation, this person would not think anything about transplanting this, or other bass, to a location where bass, and other foreign species like yellow perch, have not currently been introduced by the "bucket brigade" that has been so busy around the province in the last few years.
If I had my way, anyone caught doing any of this type of activity would be permanently banned from possesion of a fishing license, heavily fined, and spend some time in jail.