Law enforcement in China is quite flexible, depending on many factors: locations, the mood of the police, whom you know, etc, etc.
I didn't bother to report, either, before. Last time, my cousin insisted on me reporting. After all, she is a policewoman who is in charge of this. So, my dad and I went to the local police station. He brought his HuKou, which unfortunately carries a different address than the one we were staying and it was not managed by that police station. They refused the report. My dad went home angry. He complained to my cousin, who in turn yelled at the division commander of that police station, who in turn yelled at the policeman who managed the case. The poor dude called my dad back and told him that he would accept the report. The best of all, we didn't have to go to the police station again. We just needed to take cellphone pictures of my passport and my dad's HuKou and sent to him.
In China, whom you know could turn some lousy public service into one with supreme quality.