I do not think he regrets it still, and I doubt he would publicly admit it even if he did. He will be defiant until the bitter end and when he finally is cut, I doubt you will see many apologies.
I still think he believes he did the right thing because he still values Williams for some strange reason.
If it were me, I would be livid I have been embarassed by his play the last couple of years and be wearing Williams out. But that is hardly the case with this. He is still getting the kid glove treatment.