The following is totally just me spitballing, but the large contribution to that human trafficking charity really makes me wonder. My mind has led me to three conclusions.
1. Like most other uberwealthy people, he has other people making the decisions about where his charitable contributions go. This is probably the simplest, most likely explaination, especially if you want to believe that he had no idea about the potential status of the women servicing him.
2. He got pinched once before, but whoever caught him swept it under the rug, and made him do something for victims of the crime he was committing.
3. He felt guilty about his hobby and thought that maybe throwing money at that cause would help balance out his bad karma.
The last two make the most sense if he knew what was happening (or at least what commonly is happening) at a place like that.