Rather, plaintiff must "come forward with some positive evidence of negligence." Guttierez v. Albertsons, Inc., 824 P.2d 1058, 1061 (N.M. Ct. App. 1991). Specifically, "[i]n a slip and fall case, a business visitor must prove that an owner or occupier of the premises failed to exercise ordinary care by rendering safe an unreasonably dangerous condition on the premises known to, or discoverable upon reasonable investigation by, the owner or occupier."

Jury instructions not objected to become the law of the case. Gutierrez v. Albertsons, Inc., 113 N.M. 256, 259 n. 1, 824 P.2d 1058, 1061 n. 1 (Ct.App. 1991). The jury determined that any negligence on the part of Defendants was not the proximate cause of Plaintiff's injuries.

{28} Defendant has not cited, and we are not aware of, any New Mexico case applying the principle that the "exoneration of the servant operates in tort to exonerate the principal of vicarious liability" where the employee has been "exonerated" by a statute of limitations. In Gutierrez v. Albertsons, Inc., 113 N.M. 256, 264, 824 P.2d 1058, 1066 (Ct.App. 1991), we expressly declined to address the issue of whether the running of the statute of limitations against an employee bars the vicarious liability of the employer. An examination of cases from other jurisdictions indicates that "exoneration of the servant" commonly is understood to mean acquittal of the employee or agent following a trial on the merits.

Jury instructions not objected to become the law of the case. Gutierrez v. Albertsons, Inc., 113 N.M. 256, 259 n. 1, 824 P.2d 1058, 1061 n. 1 (Ct.App. 1991). Consequently, we hold that Defendant failed to preserve the argument it now makes on appeal.

. Rather, a plaintiff must “come forward with some positive evidence of negligence.” Guttierez v. Albertsons, Inc., 824 P.2d 1058, 1061 (N.M. Ct. App. 1991).

" Id. (quoting Hallett v. Furr's, Inc., 1963-NMSC-028, 71 N.M. 377, overruled in part on other grounds, Proctor v. Waxler, 1972-NMSC-057, 84 N.M. 361). Accordingly, "[n]egligence may not be presumed from the fact that an injury occurred." Gutierrez v. Albertsons, Inc., 1991-NMCA-135, ¶ 16, 113 N.M. 256 (citing Williamson v. Piggly Wiggly Shop Rite Foods, Inc., 1969-NMCA-088, 80 N.M. 591). Plaintiff must "come forward with some positive evidence of negligence." Id. Determining the existence of a duty is a question of law for the Court to decide, whereas breach of duty and proximate cause are questions of fact for the jury.

The allowable time to discover and to remove a dangerous condition or to warn of the dangerous condition depends on the circumstances of each case. Gutierrez v. Albertsons, Inc., 1991-NMCA-135, ¶ 34, 113 N.M. 256. Premises liability, however, cannot "be presumed from the fact that an injury occurred" or from "the mere presence of a slick or slippery spot on a floor...." Id. at ¶ 16; Williamson v. Piggly Wiggly Shop Rite Foods, Inc., 1969-NMCA-088, ¶ 3, 80 N.M. 591.