Canada

Except that credit scores have 0 interest in whether they're fair to the person being scored. They are profitability scores for potential lenders to evaluate doing business with someone. To that end, a lender won't care if you had a legitimate grievance against the landlord. Withholding rent even through escrow for lease violations is still likely to be viewed as problematic behavior and they wouldn't want to risk you doing the same to them.

Afaik, you can't just decide to withhold rent when there's a dispute. This would give landlords an enforcement tool other than suing and eviction, though, since that is necessary to get that enforced.