My comment:
(a) The zh.wikipedia.org says Mr 杨匡 and 河南维权人士刘沙沙 2013年9月在香港註冊结婚.
(b) I can not find similar information in China's official media (such as 人民网). I can not comprehend how a person can go into China without a 回乡证. Maybe he really snuck into China.