Aren't common? I've seen it happen all too often from old friends to people I've "sort of known" to an ex who was going to when she came back to live with me, luckily I found out before (pity emails to her "friends) or it was just an idle attempt at some sort of twisted sympathy.
There was a case over here just recently where two girls claimed someoned raped them, a year ago. Their story was riddle with innacuracies and at time were self admitting that they were in no state of mind at the time of the alleged encounter to sound trust worthy.
One said she thought she was with her boyfriend, sounds to be she can't handle her alcohol, led said guy on and he can't have been wiser to know she didn't want anything.
She admitted it was "pleasant" until she realised it wasn't who she thought it was.
I find it amazing you can even begin to believe someone can get to the stages of intercourse before knowing who you're doing it with then having the gaul to accuss rape.
His name was plastered everywhere, papers, news, online and the girls? nope.
So, does the rest of civilisation get some sort of warning on who these people are and not trust them? If I found out someone was found wrong of accusing rape like this one I'd run the hell away. These people do not give authentic cases of rape any help whatsoever, people who lie through their teeth like this are just as bad and deserve repurcussions if enough evidence against them is given.