Because...

...the fact is that by the time the case has gone to court, the boy may be so totally screwed up from having total strangers fuck with his head over what happened...that he tells the court what they want to hear. How embarrassing it must be to have these strangers with printed out photos of what was 'private' activity between two people who wanted to fool around, and then have invasive questions asked about all the gory details. Then there are the counselling industry of course and we all know their line on it. From the article it is quite clear that the boy really liked his AF, the mother says he was always wanting to go around there and never showed any signs that anything was wrong. If the AF was guilty of anything, it was getting involved in filming the activities and exchanging them with others, from where they ended up on the net. Even if that other asshole hadn't ratted on him, he likely would have been caught eventually, as by all accounts he did not hide himself in the footage. There are some who say that man/boy sex should in theory be allowed happen, but that in the current climate it is just too risky for all involved because of what happens when it gets found out, and i guess this case is evidence of this.