Your source does not back up your claim. The founder said he didn't use the slur.
Did we read the same source? The closest thing I saw in there to anything he said was:
> When discussing how he would distance himself from racist groups, Mr Schnatter said that Colonel Sanders, the founder of KFC, had never faced criticism for using the N-word, Forbes reported.
He doesn't. I think you misread this passage (it's the only thing that comes close):
> When discussing how he would distance himself from racist groups, Mr Schnatter said that Colonel Sanders, the founder of KFC, had never faced criticism for using the N-word, Forbes reported.
He admitted that he said it (https://www.businessinsider.com/papa-johns-founder-apologize...) and years later he said that not saying it anymore was one the goals he'd been working on (https://www.businessinsider.com/papa-johns-ceo-2-years-remov...)