How is this for stupidity and favouritism? UK?

A man who was respected, well educated, and middle cl, with a clean record, had downloaded hundreds of images of little children, and his defence put the case that as he was taking medication for Parkinson's disease, it supposedly increased his ual desires and the woman judge basically let him off. Whereas, and though i do not condone it at all, a woman went to jail for 18 months for going with a boy of 15, and somehow that just about sums the idiocy of our justice in the UK. The fact that he had ographic material on his PC, and the fact that he had downloaded an image before he became ill, which was not made known to the court should have resulted in a custodial sentence, and for him to be put on the offenders register. Why is one a lesser crime?