Page 9 of the MSA statement

Apple employees are able to report concerns through a dedicated helpline, via email, online or by phone. Reports can also be submitted anonymously through an independently managed third-party helpline, Ethicspoint, available 24 hous a day, seven days a week in 20 languages. Employees can access the service through local toll-free numbers provided on our website and through Ethicspoint's website. All reports are assessed and investigated, as appropriate. p. 9

Our Code and Standards also require that all supplier employees have an effective grievance mechanism to report grievances. In addition, we provide thrid-party anonymous hotlines and the ability to contact the Apple ESCI team directly at any time and in any language. When an issue is raised, supplier management is required to immediately investigate and to resolve the issue in a timely manner. p. 7

"anonymous" reporting possible, which covers "whistleblower protection"