Ouch. As with everything workwise leaving a company should be a team process.
We are all human and in 12 years of service we will inevitably forget a few things. It is in this context, I suppose timely to remember that there will be ex colleagues who will also inevitably attempt to score a few points with the company against those who are not able to respond. However to post an article on a public platform quoting details. Well, words fail.