One of my aunts married a catholic and this very thing happened to her son. Of course in hindsight it was easy to see the problem since the family let a priest sleep at their house...in the same room as their son...as well as travel with him.
The problem is people think priests are somehow above having human failings. Almost as though they think they are exactly like Jesus...without sin. The Pope is no different. He is not exactly like Jesus at all. As long as we are in this flesh and allow satan to tempt us, we will fail.
The priest involved committed suicide when he was confronted...so it never went to trial. It caused my cousins to either come out of the catholic church to protestantism or they fell away all together.
That being said...this sort of thing can happen in any church...but the way priests are taught to be celibate (not married), seems to only encourage failure and a rise in homosexuality and child abuse.