Abu Sin knew what he was doing. Sometimes incarceration is a risk you take to try and make a cultural change or statement.
Abu Sin was a young boy talking to a woman. To say he fully understood the ramifications of his actions is absurd. He almost certainly knew it was a social taboo, but to say he was trying to make cultural change is really stretching. We do not know his intentions, but Occam says hormonal teenager trumps activist any day.
That said, this probably happens quite a bit with teenagers, just not out in the open. Then, afterwards, after the physical and mental scarring endured, these young men learn hate. And that hate is not towards his oppressors, the regime and religion that beat him down. Instead it is twisted at women or those who do as they did, that they should suffer the same punishments. This is how these types of systems stay in place and prosper.