Legal Question in Business Law in California

"Collusion is an agreement between two or more persons to defraud a person of his rights by the forms of law or to obtain an object forbidden by law. It implies the existence of fraud of some kind, the employment of fraudulent means or of lawful means for the accomplishment of an unlawful purpose, a secret combination, conspiracy or concert of action between two or more persons for fraudulent or deceitful purposes." Xebec Development Partners, Ltd. v. National Union Fire Ins. Co., 15 Cal.Rptr.2d 726, 12 Cal.App.4th 501 (Cal. App. 6 Dist., 1993)

I don't know whether the term "collusion" is defined differently in the employment agreement or whatever the former employer is relying upon in calling what happened collusion, but I doubt that what happened fits most definitions of collusion commonly used in the law, using the definition in the Xebec case as rather typical.

Unless there is an unusual definition or other facts, I'd think the employees here would prevail in court against any legal action taken by the former employer. In addition, California law and policy is rather favorable toward employment mobility.