If this were the case, why not just get Clive's permission up front and avoid the uncertainty?
If I were to write a story about a fan-girl obsessing over Clive, I probably would seek his permission as he is something of a wild card and is entirely likely to respond in person with permission or denial. I doubt he is inundated with requests. Someone with a large and rabid fan-base, such as the aforementioned Mr Pattinson, or perhaps Mr Smith or Mr Tennant, the former Doctor Whos, seem different to me. There are literally thousands of pieces of fanfic out there where they are clearly identifiable as characters. I can only imagine they have received umpty million requests for permission to do all sorts of things with their image, to the point where they probably don't even bother to reply to the request.
Say I were to write a book called The Stalking of Mr Smith where-in the main character obsess over Mr Smith, but never actually meets him, hears from him or interacts with him in any way except via their fervid fantasies and trawling through the media for glimpses, am I actually using a real person in my story, or some kind of meta-person? I'm not really sure. I know that my 12 year old daughter could probably write this story right now, seeing as she devoted about a year of her life to doing just that!