'Does T. Ray know what you're doing?'
'T. Ray don't know nothing.' These sentences are from the bestseller The Secret Life of Bees by Sue Monk Kidd. The whole book is also a text for discussion in the present CPE exam.
I don't understand why the writer uses 'don't' instead of 'doesn't' in the second sentence.
It is very strange to me, while the dual negative structure is not, I have come across with it several times.
But using 'don't' when refering to a person who is not present, I cannot explain. Would it be accepted in modern American English? Or does it have a special meaning, context, connotation? Thank you for help.