The appeal is dismissed.

The costs of appeal are assessed against the defendant.

We examine the grounds of appeal.

1. As to the ground of appeal on the existence of the Plaintiff’s right to indemnity against the Defendant

A. 1) Workers’ disaster security insurance (hereinafter “workers’ accident insurance”)

Under the terms and conditions of the Industrial Accident Compensation Insurance Act (hereinafter “Industrial Accident Insurance Act”) which is mandatory insurance among the liability for damages to be borne by the insured due to occupational accidents occurred to the insured workers.

(iii) the extent of the amount to be transferred by the Corporation (hereinafter referred to as “industrial property compensation amount”).

(2) If the Korea Workers’ Compensation and Welfare Service determines that the insurer is liable for compensating for the excess portion only, the risk that the insurer takes over is limited to the loss arising from the insured’s liability for compensating for the excess portion of the industrial accident compensation portion, and thus, the insurer is not obligated to pay insurance proceeds for the industrial accident compensation portion (see, e.g., Supreme Court Decisions 2012Da1870, Jul. 10, 2014; 2009Da8581, Jan. 12, 2012). In other words, the Korea Workers’ Compensation and Welfare Service bears the duty to pay industrial accident insurance benefits for the industrial accident compensation portion among the liability for compensating for the damages suffered from the occupational accident, and the insurer of the industrial accident insurance bears the duty to pay insurance proceeds only for the excess portion. (2) Meanwhile, if a third party, who is not the obligor, pays another person’s debt with the intent of paying the liability of a third party and the obligee is aware of such circumstance while receiving the reimbursement from a third party.

(see Supreme Court Decision 2009Da71558, Feb. 11, 2010). A third party without an interest cannot make reimbursement against the obligor’s will. An obligor’s counterclaim should be clearly recognizable in light of the objective circumstances at the time of repayment by a third party. The obligor’s counterclaim should be able to infer the obligor’s objection to nullify the effect of repayment by presumptioning the obligor’s objection to a third party.