I think that the reason people are so opposed to this is that they see sex has harmful. they see it as the man (father) somehow doing something *to* the girl (daughter) which is certainly possible... it happened to my cousins... but that isn't always the case. sex *should* be something two people who love eah other do together... ie the kind of sex (i like to believe most) married coupples have... but, for some reason, so many people seem unable to comprehend that a father and daughter can have that same bond... although I find it unlikely that such a bond would occur with the mother still present or with any brothers around. I think studying phychology might help those so opposed to it understand what's going on here. My belief is that either 1) it's a way of the father excersising his dominance over his daughter (which I find absolutely deplorable) or 2) a very complicated relationship between the father and daughter where feelings that would normally be towards others end up displaced onto each other: likely the mother is no longer present or is emotionally withdrawn. the feelings that would normally be felt towards her then have to go somewhere and if there is not another mother figure present then the father ends up as both the mother and father fogure. Now, everyone knows that a mans first love is his mother and a girls first love is her father. So, that combined with the aprochability/equality relationship that the girl has displaced from her mother to her father opens up the possibility, in her mind, for true romantic feelings towards him. And then, then she has sexual urges, they become tied with the feelings of romance and she starts to desire to be with her father. Also, it is likely that by now she has begun to see herself as a replacement in his life for her mother and feels that a sexual union would solidify the bond of husband/wife between the two of them. Now, in the fathers head his duaghter is, as it should be, the most important person in his life. He is the sole nurturer for her and she is likely the only female that he is able to nurture. Men, by instinct, feel the need to protect their mates and offspring. Because she is the only female that he is close to and she has been treating him like her husband when she makes an advance he will probably be uncomfortable but eventually give in 'to make her happy' and will eventually fall in love with her in the same way that he loved her mother. Something important to pick out here is that the daughter has seduced the father. That is actually a lot more common than most people realize, and I don't have a problem with that.
Now, regarding the situation mentioned in the article.... it certainly sounds like it's situation number 1, HOWEVER we don't really have enough information do determine if it was 1 or 2. Innocent until proven guilty, right?