You should have the following in the contract/agreement that your client signs
“This is not a Building Code, title, nor By -law compliance inspection and is not to be construed as such.”
If something is clearly wrong and would never have been passed by even a blind building inspector, I advise the clients to check on a permit. The owner is responsible for permits regardless of when they assume ownership.
Chances are you work in several counties towns and cities, are you willing to keep up with all their differences?