Exploitation of False Internship?

[Ronald]

Although I've rarely had an issue with her, the supervisor/manager where I work is pretty unprofessional, generally disliked, and talks poorly about employees during other employees' reviews. Back when I was finishing college (over three years ago), I attempted to get an internship at the company, but it fell through and so nothing happened. I continued my job as usual.

A few weeks ago, a coworker of mine told me that during her review, the supervisor oddly told her that the only reason I'm employed at the company is that I had an internship, perhaps suggesting that they get a tax break or something. I'm positive none of this regarding my employment is true, as I'm highly skilled yet not full-time and therefore they pay no benefits. I've been a good asset when employees have been fired or quit in my department.

It would really bother me if the company somehow had it in the books that I had an internship with them and therefore receive some sort of benefit from that. Is that possible? I wouldn't put it past them as they've allegedly done a great deal of sneaky, underhanded things. But how could I find out, just outright ask my supervisor? Or is there a resource I could seek out, considering the issue does involve my employment/education and I have the right to information regarding that? With a new full-time job next week, I'm nearing my end with the company but would like to take action on this if possible. I even have a small audio recorder in case I would ask my supervisor of the issue.