New York (CNN Business) — Roger Stone, the political operative who avoided 40 months in prison after US President Donald Trump commuted his sentence earlier this month, denied on Sunday using the word Negro on air toward a Black radio host. The exchange took place on Saturday during Stone's appearance on "The Mo'Kelly Show," a Los Angeles-based radio broadcast. Host Morris O'Kelly questioned Stone on his conviction for lying to Congress and tampering with evidence by threatening a witness involved with Trump's 2016 campaign. He then asserted that Stone's sentence was commuted because of his longtime friendship with Trump. "There...