(a) If an affidavit claiming a mechanic's lien is filed by a person other than the original contractor, the original contractor shall defend at his own expense a suit brought on the claim.
(b) If the suit results in judgment on the lien against the owner or the owner's property, the owner is entitled to deduct the amount of the judgment and costs from any amount due the original contractor. If the owner has settled with the original contractor in full, the owner is entitled to recover from the original contractor any amount paid for which the original contractor was originally liable.