Why has Scott McCarron apologised to Phil Mickelson?

Question

After McCarron accused Mickelson of cheating at the weekend, Mick in turn referred to the comments as "slander," and hinted that he'd be taking the matter further. Now McCarron has offered an apology to the world No. 2. "I'm certainly sorry for it," McCarron said. "I'd like to apologise to Phil Mickelson for what I said. We both realise we’re on the same page on this issue."