This was an interesting read! I hope they do a follow up article on how they automatically manage the rest of their recovery process.
In this case, the recovery (repair) of the system (that is, to bring it to a clean state) simply consists in deleting the file (see https://docs.oracle.com/cd/E26505_01/html/E37384/gbbbc.html#...).
If there was an intact copy of the file available in the mirror, then one doesn't need to do anything, as ZFS is self healing: https://blogs.oracle.com/timc/demonstrating-zfs-self-healing.