A job listing is filled out with the correct title, but when you try save it as a draft it says you have to fill out the job description. Type in some blah-de-blah text, maybe a joke for the person that is meant to fill it out. Save it as draft.

Boss comes along and asks the administrator "Can you post that Environmental Officer job?", the administrator finds the job listing via the title, and may only see a snippet of the description, or doesn't read it at all, publishes it.

It's a documented problem that using semi-real looking filler text, like Lorem Ipsum, is a bad idea. It often gets accidentally published. It would have been better just to put in a couple of paragraphs of "XXXXXXXXXXXXXXXXXXXXXXX" or something.

This is most likely not the exact steps that happened, but is a theory on how it can. Or they got hacked or a disgruntled employee.