Nothing in sections 57-801 to 57-820 shall be deemed to fix a greater liability upon an owner in favor of any claimant under an original contractor than the amount for which the owner would be liable to the original contractor. The risk of all payments made to the original contractor shall be upon the owner after the receipt of notice that a lien is claimed and has been filed as herein provided by a person other than the original contractor. An owner shall not have the right to offset obligations of the original contractor unless such obligations arise out of the original contract.