Employee Records?

I was employed as an assistant manager for a national company in the entertainment rental business. In September 2002, I was rather abruptly terminated from this position. I understand the concept of At-will employment. What I don't understand however is how then after said termination I could be classified as "non-rehireable" by a single person. (In this case a District manager). I would think that this is just one man's opinion and as such could fall into a defamation suit as a few other people I spoke with including Store Managers for said company, wouldn't have terminated me.
In addition this was not a termination of an illegal nature (ie I did nothing questionable within breaking the law of the state...theft of property, illegal drug use, etc) and even was awarded unemployment benefits in the state of Maryland after being terminated.

My main question after these facts, is there anyway to have have that portion of my employeee record expunged or at least the status of non-rehireable changed to re-hireable?
I ask mainly because I have now re-located from Maryland to Illinois and quite honestly I enjoyed that job, the company in itself a majority of the time, and overall I was really good at what I did. In fact one store manager for this company is also still a job reference for me in my current job search. And I know that the company is looking for the same positions here in my new region, but with the advent of modern technology and screening processes this company uses the "C.A.S.T" by Unicru, I wouldn't even gain an interview, because I would show a "red flag" as non-rehireable.

Any advice on this would be appreciated.