If the person's job is not impaired by them missing or leaving early, and all their work is getting done, why would management really care? The work is getting done. If its a salary job, then it shouldn't matter to anyone, get the work done and management should be happy, paid the same. If its hourly, then the worker is just getting paid less and management shouldn't really care as long as the work is done.
If their work isn't getting done, then management will find out and fire them.
If that user is so mad because they're covering up their absences and doing all their work, maybe they shouldn't and let management know its an issue.
Edit: The OP in that thread actually said the employee is getting all their work done, but it always "contains the same mistakes, so we have to fix it". Sounds like they're too incompetent to train the employee to do the things correctly, or refuse to tell management that the employee can't learn.
If Morrigan was still a shitty mod, how fast would this guy be banned