Thе only substantial question in this workmen’s compensation case is one of fact, — one of medicаl causation. We found it necessary to have a rehearing because of uncertainty in the court on the method of discharging our duty of fact finding as delegated by the legislature.
Claimant had acutе epididymitis, that is, an inflammation of a portion of the testicle. The hearing officer and the Workmеn’s Compensation Board found the ailment was not caused by an industrial accident and, therefore, was noncompensable. The circuit court found it was caused by an industrial accident and was compensable.
A detailed statement of the evidence and the opinions of the hearing officer and circuit court is unwarranted. Except to the parties, the only importance of аn appellate opinion in this case is as a statement of the application of previously announced principles for de novo review of workmen’s compensation cases.
*441
In
Coday v. Willamette Tug & Barge,
In
Romero v. Compensation Department,
The hearing officer in this ease opined that the claimant’s credibility on the issue of the cause of his ailment was questionable because he had been impeaсhed. Study of the transcript does not lead us to the same conclusion. The claimant was inconsistent upon a collateral matter. Nevertheless, taken in the entire context of claimant’s tеstimony, this inconsistency alone does not cause us to doubt the witness’s credibility. It could be that something else about the claimant caused the hearing officer to doubt his credibility; however, the hearing officer only mentioned the alleged impeachment as the reason for his doubt. In addition, there was no evidence, direct or indirect, of any cause of claimant’s condition, other than that stated by the claimant.
The hearing officer questioned the attending physician’s opinion on causаtion because the physician incorrectly stated a critical portion of the history. The рhysician did not personally testify; only his report was in evidence. The entire record causes us to con- *442 elude that this statement was inadvertently made and the physician knew and took into account the correct history.
The medical evidence favorable to the insurer, the defendant, was largely statistical. It is to the effect that a small percentage, if any, of acute epididymitis сases are caused by strain. The treating physician, the only physician familiar with claimant’s case, concluded that the industrial strain reported by claimant was the cause of his condition. True, the physician reached this conclusion, based upon the history received from the claimant and his findings and observations, because he could not account for the condition by any other means. This is nоt the strongest kind of reasoning; however, our experience has taught us that this is sometimes the only way in whiсh medical causation can be determined. Taking into account the agency’s expertise and the hearing officer’s opportunity to observe the witnesses, as triers of fact we, neverthеless, find that industrial strain caused plaintiff’s condition and he is entitled to compensation.
For clarifiсation of the procedure in future hearings we decide another assignment of error. The hearing officer, over claimant’s objection, received a memorandum by a doctor into evidеnce. The memorandum concerned Lucke’s claim. It quoted from several medical texts and thе author of the memorandum concluded that only a small percentage of cases of аcute epididymitis was caused by strain. It is contended that this report should not have been received into evidence because it was an abstract opinion, not based upon any examinatiоn or history of Lucke. The hearing officer based his ruling upon ORS 656.310, *443 which authorizes the receipt of medical reports. In addition to that statute, OES 656.283(6) provides:
“Except as otherwise provided in this section and rules of procedure established by the board, the hearing officer is not bound by common law or stаtutory rules of evidence or by technical or formal rules of procedure, and may conduct the hearing in any manner that will achieve substantial justice.”
The exhibit had some probative value. The ruling of the hearing officer was correct.
Affirmed.