Bartholomew didn't completely buy this guy's story. He too was a cunning man and could easily recognize his kind.
There must be something related to her that he wants.
But for the sake of peace and his own benefits, he chose to stay silent, letting everything think whatever they believed to be so.
In the end, it was true she was a slave when he met her.
He had no true way of knowing her past unless his gifted son decided to aid him in finding the truth out.
But why would he draw the bit out of his busy cultivation time to worry over a nonimportant woman?
There were as many slaves as there were stars in the sky.
So if everyone had to worry about each and every slave, won't they grow bold before old age catches up to them?
In a way, it was good he was getting rid of the duo, lest any real issue Rita had caused in the past would affect him.