From the article:
Whitaker, a CNN legal commentator, wrote last month that President Donald Trump was “absolutely correct” when he said it was a “violation” for special counsel Robert Mueller to investigate the Trump family’s finances.
If I am incorrect that a CNN Legal Commentator is an employee, I apologize.
According to the above link he “regularly appears on CNN as a legal commentator”.
I don’t think his appearances on the network qualify as employment per se, but I suppose he must be compensated by CNN for being on panels to discuss legal/political matters. More like an on-call contractor working under an agreement rather than a salaried employee.