Why should he have to apologise for this? This is normal 'robust' conversation between an employer and an employee who have a disagreement.
The driver is apparently bankrupt (well done), so I would not be at all surprised if he deliberately tried to bait Travis into this conversation so he'd have a story to sell. At the end of the Bloomberg article where this surfaced, they noted that the driver got 1 Star for that ride - I find it hard to believe that anyone other than Uber and the driver would have been able to know that.