Okla. Stat. tit. 85A, § 85A-68: Rebuttable presumption injury not work-related

A. Unless an employee gives oral or written notice to the

employer within thirty (30) days of the date an injury occurs, the

rebuttable presumption shall be that the injury was not work-

related. Such presumption must be overcome by a preponderance of

the evidence.

B. Unless an employee gives oral or written notice to the

employer within thirty (30) days of the employee's separation from

employment, there shall be a rebuttable presumption that an

occupational disease or cumulative trauma injury did not arise out

of and in the course of employment. Such presumption must be

overcome by a preponderance of the evidence.