Employers may not disqualify job applicants for a position because the applicants engaged in protected whistleblower activities during prior employment. Examples may include disclosing information that they reasonably believe was illegal, race or gender discrimination, and health or safety issues.
Unfortunately, most whistleblowers will find it challenging to prove that prospective potential employers declined to hire because of prior whistleblowing activities instead of other legitimate business reasons. Legitimate business reasons for declining to hire candidates could be factors like experience, education, recommendations, etc. Since prospective employers will rarely say why they decline to hire, a victim of whistleblower retaliation in hiring would probably need access to evidence from a friendly witness who already works inside the company to provide helpful information on the genuine reason for no hire.
(See Link(s): Labor Code Section 1102.5)