“The complaints come in a few different varieties: People who've actually been held too long and people who ask to see their release date and realize there's an error before the day comes. (DOC says some people are also released early because of errors, but they don't tend to complain.)”
Folks have been released early.  Did you read the article? If you knew how the system worked, you’d understand how that would be possible.  DOC would have to go back and audit every single persons time accounting records to determine how many were released early in error. That would be so time consuming and expensive it will never happen.  Again in the vast majority of the small number of cases, it’s a day or two.  This article makes it sound like every person is being kept in jail for months longer than they should.  That’s just not the case.