【明報專訊】THE other day Japan Coast Guard vessels collided with a Chinese trawler. The boat, its captain and its crew were detained. Yesterday the boat and fourteen members of its crew were allowed to leave. However, Zhan Qixiong, its captain, remains in custody. Japan still intends to deal with him under its domestic law. Clearly, though China has repeatedly pressured Japan through diplomatic channels, it remains essentially the case that Japan virtually exercises sovereignty over the Diaoyus.