I respectfully dissent. In my view the determination of the Comptroller is not supported by substantial evidence. The testimony of Dr. Harwood, the orthopedic specialist who testified on behalf of the Comptroller, insofar as he expressed a psychiatric opinion, should be rejected. The evidence in this record establishes that while petitioner’s physical injury was not of such severity as to be the sole cause of his permanent disability, the injury nevertheless "triggered” or set in motion in him, a *929reaction resulting in his psychiatric breakdown and his permanent disability. To the extent that Dr. Harwood’s testimony may be said to be in contradiction of this conclusion, in my judgment it is not supported by the evidence in the record and may be disregarded (Matter of Palermo v Gallucci & Sons, 5 NY2d 529, 535). In Matter of Palermo v Gallucci & Sons (supra) Judge Van Voorhis, in a cogent dissent, stated (p 535): "Medical opinion evidence has no greater probative force than the grounds on which the testimony shows that it is based. It must be viewed in the light of the record as a whole, and evidence which unexplained might be conclusive may lose all probative force when supplemented and explained by other testimony (Matter of Kopec v. Buffalo Brake Beam-Acme Steel & Maleable Iron Works, 304 N. Y. 65, 71; Matter of Reihl v. Town of Amherst, 308 N. Y. 212, 215-216).” When Dr. Harwood testified that petitioner "is not disabled as a result of the accident of 1975”, he was responding to the question concerning the petitioner’s physical disability, and he answered from an orthopedic standpoint, not from a psychiatric point of view. Dr. Harwood made this distinction clear when he stated that he did not pass judgment on the connection between petitioner’s incident in 1975 and his emotional and/or psychiatrict problem. Moreover, the hearing officer preserved that orthopedic-psychiatric distinction throughout the hearing. Dr. Harwood did opine that petitioner’s disability was in his back because that was where he centered his problems to be and that he could have picked it to be in his right ear or big toe. However, Dr. Harwood admitted that his opinion may be just a guess. He then stated that the basis for his guess was his "observations of people who have been injured or struck in the back and are taken to the emergency room and then sent home and then come in to see their doctor a while later.” The difficulty with Dr. Harwood’s observations is that the record indicates petitioner is not such a person. Petitioner’s undisputed medical history is substantially different. Petitioner’s history is that of a person who had substantial complaints shortly after the accident and continuously thereafter. He was also under continuous medical care from the beginning. Dr. Harwood indicated that he obtained a very meager medical history from the patient. It is obvious from the record that Dr. Harwood was not familiar with many of the details of petitioner’s medical history and apparently had other persons in mind when he testified. Surmise and conjecture are inappropriate foundations for an opinion. Therefore, Dr. Harwood’s psychiatric conclusions relating to the question of whether petitioner’s psychiatric disability was the natural and proximate result of the accident of December 24, 1975 should be rejected. The determination should be annulled and the matter remitted for further proceedings.