The import hook in CPython that handles legacy *.pyc files (SourcelessFileLoader) is incorrectly handled in FileLoader (a base class) and so does not use io.open_code() to read the .pyc files. sys.audit handlers for this audit event therefore do not fire.
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2026:10950 https://access.redhat.com/errata/RHSA-2026:10950