As someone who works in a forensic lab, a lot of physical evidence could be anything. Testing hair found in a shower drain trap. testing sheets, towels, and clothing for body fluids. They would have combed through the carpet for stray fibers and hairs. Here is the thing IT HAPPENED IN A HOTEL ROOM. They are the worst place for a crime to occur, if in fact any crime did happen. Even with housekeeping cleaning the room everyday there would still be "evidence" that does not belong to the people allegedly involved in the crime. As for the DNA sample from Kobe, maybe she says it was Kobe but in fact some one from his entourage then the police would collect the sample from the person the victim states did the crime and she is claiming it was Kobe.
From what I have read about Kobe, he loves his wife. I don't think he would do anything that would damage that relationship.