They cannot even prove that there was even a crime committed at the house. That the nurse said the condition of the dancer was consistent with rape is also saying that the condition of the dancer was consistent with consensual sex.
There are posts in various early threads (when the photos came out) that people saw bruises on the woman when she showed up to "dance" or whatever it is strippers do in a small room with 47 other people.
There are some discussions about that possibly being a source of concern on the part of the audience ~ a beaten up stripper is hardly the entertainment expected (although I wouldn't know from personal experience ~ maybe guys who hire strippers like them beaten up or something although that's doubtful).