You've referred to acquaintances of Duck as white hood wearers. That's an accusation of racism. If I regard myself as an acquaintance of Duck, then you consider me a racist. The apology doesn't alter the allegation, and as you rightly say, it's not for you to say how words impact.
You've made your point repeatedly, and have become a bit loose with your comments. Winding your neck in would be a good idea imo.