In Pacific Indem. Co. v. Industrial Acc. Com. (1950) 34 Cal.2d 726, a statute of limitations defense was rejected and the award to the petitioner affirmed. There petitioner was a flight instructor and in 1942 while flying developed symptoms of tuberculosis. The treating physician did not advise the condition was industrial. Petitioner inquired through his wife whether his condition could be compensable and his employer advised that it was not. Petitioner then sought treatment and rest for several months. After four months the employer called and requested he return to work in the control tower. After two weeks he was reassigned to flight instructor duties. A physician's report in May 1943, showed the preexisting disease to be arrested. As a flight instructor, petitioner was in the air six days a week for long hours. He was subjected to changes in pressure and temperature. In February 1944, while "rocking" the wing of an aircraft, he felt "catches" in his chest and later expectorated blood. ( Pacific Indem. Co. v. Industrial Acc. Com., supra, 34 Cal.2d 726 at p. 727.) In May 1944, he had a similar experience. in July 1944, feeling tired he left work and stayed at home to rest. On November 16, 1944 he learned from his physician that his tubercular condition had been reactivated by his work. He applied for benefits on February 9, 1945. The evidence was found ample to support a finding that his work caused the reactivation of his condition. In regards to the necessity of filing the claim before being medically advised of industrial causation, the court said: "Specific applications of the rule date of injury show that merely because the employee had some symptoms is insufficient to sustain the burden; that the employee is not required to be versed in medical knowledge, and thus, that it is not fatal that he made a mistaken diagnosis of his trouble. testified that he first discovered on November 16, 1944, that his disease had become reactivated. There is no direct evidence whatever that prior to that date he knew he had a compensable condition -- that his condition was caused by his employment. No physician ever advised him that his ailment was employment connected. . . . When employee became ill with tuberculosis in the first instance (1942), his doctor did not advise him that it was caused by flying--his work. He inquired of his employer, through his wife, as to whether the original attack was compensable and was advised it was not. Although the fact that he inquired indicated that he thought he might be entitled to compensation, such thought was banished by his employer." (Pacific Indem. Co. v. Industrial Acc. Com., supra, 34 Cal.2d 726 at p. 729.)