This case is strange, the money is almost certainly from drug dealing.

IANAL, consider two other situations:

• The couple never discovered the money, they sell the house in 20 years...the crown never sees any of it.
• The couple discovers the money without the electrician, they tell no one and slowly spend the cash, the crown gets the GST portion of the money back...

The other point I would make as the lawyer in this case is "How would taking this money; prevent future crime?"

The legislation is used by police to separate criminals from their ill-gotten gains, fighting crime by confiscating the profits that make it worthwhile.

The compromise the crown could make, is that the money is taxed as income. They get 33% + 15% of any money spent.

The moral of the story, is if you find a butt load of cash, don't tell anyone.