Racists like Mills need to be counter-attacked, because defending oneself will be pretzellated into evidence that one is a racist. The host of that BBC set-up deserved to be attacked as well.
My opinion is that one should never go on the defensive when accused of racism; the term has been distorted into meaninglessness and nothing is gained by defending against it. On a couple of occasions I've simply said "I don't care what you call me" and re-iterated my argument; that definitely took the air out of the "racist" charge.
Bolling should have immediately demanded of BBC host Emily Maitliss that she explain why she and the BBC would allow demeaning racial stereotypes to be used on their programming. Maitliss and the BBC are accountable for what they allow to air, just as American networks are accountable for what they allow to air; Rs and Conservatives should immediately hold the media accountable for allowing this, and if the program moderator does not call out this racism immediately and clearly, then it's time to get up and walk off.