Oregon Revised Statutes Labor and Employment; Unlawful Discrimination § 663.215

(1) No objection that has not been urged before the Employment Relations Board shall be considered by the court, unless the failure or neglect to urge the objection is excused because of extraordinary circumstances. The findings of the board with respect to questions of fact, if supported by substantial evidence on the record considered as a whole, are conclusive.

(2) If either party applies to the court for leave to adduce additional evidence and shows to the satisfaction of the court that the additional evidence is material and that there were reasonable grounds for the failure to adduce the evidence in the hearing before the board, the court may order the additional evidence to be taken before the board, and to be made a part of the record.

(3) The board may modify its findings as to the facts, or make new findings, by reason of additional evidence so taken and filed, and it shall file modified or new findings. With respect to questions of fact the modified or new findings, if supported by substantial evidence on the record considered as a whole, are conclusive.