It is pretty much SOP to name individuals as well as the corporation in suits such as this to cover all of your bases. From the fact that companies can find paperwork holes to place the blame on the particular individuals as well as the fact that most of the time, a named individual won't have the dime necessary to procur the legal defense that a company will. Deep pockets and what not.
Also, as I said before, while the "he made fun of me" is a small part of the defamation portion of the suit, the main ingredient is that fact that public statements were made about Barnes being fired. Even if it was a choice by one or both parties to not renew an expiring contract, most of the time there is language stating that both parties mutually agreed to disengage, for the very purpose of avoiding the "I quit" or "he was fired" to ever come into play. That being said, in employment law, it is very bad to make public statements about the nature of someone's employment, particularly the nature of the disengagement. This is the big deal in the defamation portion of the lawsuit, not the fact that someone said he had a skin condition. If you left a company on mutual terms and all of a sudden they sent a memo to everyone in your industry that you had, in fact, been fired, this could potentially affect your employability in the marketplace and is a big no-no in labor practice. The courts are particularly keen on statements of this nature when they are not true, especially in small market scenarios. If you were a sales person, it's not as big a deal because there is less of a public perception and there are probably 1000 sales jobs in the city. In this arena, however, there are maybe 4 viable companies and maybe 8-10 positions. That being said, the court could easily decide that making statements that someone was fired, when in fact they weren't, could very adversely affect that persons ability to persue employment in that marketplace. And the courts are funny when you start damaging peoples potential to make a living, especially in Georgia. This is the reason it is so very difficult to enfore non-compete contracts in this state.