Catholic culture is awesome much to my confession, even though I'm Protestant. I'm guilty sometimes of loving Catholicism more than my own. Catholics are cool and very accepting folks. They have a hot temper when you attack them or criticize them, but they are awesome religion nevertheless. But I notice ex-Catholics will still talk good about their religion, though having doubts.
If teenage rebellion is any indication of human nature, which I sincerely believe it is, then it stands to reason that a person who leaves a religion, any religion, is highly likely to do things in direct opposition to their former beliefs. For example, a Jewish man who leaves the Jewish faith may obstinately refuse to continue observing Shabbat just to prove to himself he is now free of that requriement. Certainly teenagers who are kept in a box have a tendency to explode into abnormal and risky behaviors when they turn 18 and are free of the box.
If anything I would say it is the very stringent rules of Catholicism that would create the same effect with an adult. But of course it would all depend on why a person chose to discontinue their observance of their religion. A Jewish man might have only stopped being observant because he felt that God didn't really need him to follow 613 rules for life in order to accept him. Or in the opposite case a Muslim woman might have disavowed the Koran because she felt like she has every right to casual sex and will now go forth and do that.
In any case, I think the argument that a Catholic is more or less likely to do something or behave a certain way after leaving the Church completely leaves out the reality that any individual can act out or not given certain circumstances.