Okla. Stat. tit. 12A, § 1-9-626
Oklahoma Code Comment
Section 9-626, as well as providing a rebuttable presumption rule, allocates proof burdens in a manner consistent with case law under former section 9-504 . See Dynalectron Corp. v. Jack Richards Aircraft Co., 337 F. Supp. 659 (W.D. Okla. 1972); Grumman Credit Corp. v. Rivair Flying Service, Inc., 845 P.2d 182 (Okla. 1992); First National Bank and Trust Co. v. Holston, 559 P.2d 440 (Okla. 1976); and revised section 9-626(a)(1) and (2) (burden of showing compliance on secured party).