This I can't find an article or reference on. I'd kindly ask you to post it. On the internet people will believe anything if it affirms what they want to believe.
I can't say he's a bigot because his movies and character portrayals are far too complex and but authentic to warrant him being a bigot. Quentin I can tell puts a lot of work into reading and trying to understand people. His movies are more about the depth and reasoning behind characters than they are about the actual film itself. You see this from Pulp fiction, Kill Bill, True Romance, Django, Hateful 8, Reservoir Dogs, and many others. He is not ignorant or stupid at all.
Tarantino loves to push buttons and go off the deep end. A lot of his films wouldn't be as successful without that element IMO. If you're the socially sensitive type or conservative you won't like him. People take what they want out of film. Someone pointed out that 90% of Scorsese films say it, half of Francis Ford Coppola films said it but y'all love Scorcese and Francis' the Godfather series.