"Under the new law, an employer cannot require, as a condition of taking sick time, that an employee search for or find a replacement worker to cover the hours during which the employee is absent.... The Ordinance creates a rebuttable presumption of unlawful retaliation automatically when an employer takes adverse action against an employee within 90 days of when the employee: [1] Files a complaint or alleges a violation of this law; [2] Informs 'any person' about an alleged violation of the law; [3] Cooperates with an investigation or prosecution of an alleged violation of the law; [4] Opposes any policy, practice, or act that is unlawful under the law."