Dr. Will was the greatest winner by lying to everyone. He's very honest about his game and if he gets voted out for going back on his word, so be it. Nicole also calls out people for double crossing, then two seconds later contemplates doing the same thing.
At this point you have to, to win. On the other hand, he has pretty much laid down his game for Natalie and understands he has to agree with her while doing what's best behind her back.
Just my opinion, of course.