13 The learned Commissioner erred in giving weight to the matters to which I have referred and allowing them to persuade him that the successful employer should be denied costs. Save that it was submitted that the learned Commissioner was entitled to have regard to the beneficial nature of the legislation, counsel for the worker did not submit otherwise. However, the worker's counsel submitted that notwithstanding these errors, the order for costs was sound as the conduct of the employer during the proceedings and the hearing was not reasonable and unnecessarily inflated the costs. The conduct complained of was the failure of the employer to concede that the worker was suffering from a disease within the Act, s25(1)(b). This concession had been sought on behalf of the worker prior to the hearing of the claim at a conciliation conference and by a letter to the employer's solicitor. The worker had provided the employer with particulars of the conduct and behaviour of the employer, or circumstances and matters caused by the employer, which were responsible for her disease and incapacity for work. Counsel for the worker contended that as the employer was aware of the basis upon which the worker's claim was put, it was unreasonable for the employer not to concede the existence of the disease alleged by the worker. I reject that submission. It was reasonable for the employer to put the worker to proof in relation to her disease. This enabled the employer to elicit evidence from the worker and her witnesses which was necessary for the employer's case. Making the concession sought would not have significantly reduced the costs of the proceedings. The learned Commissioner said: