Disclosures by released bookseller Lam Wing-kee of his treatment in mainland China and the resultant outcry have spurred Chief Executive Leung Chun-ying to ask for a review on the notification mechanism between police forces of Hong Kong and the mainland. But the most serious allegation of Chinese misconduct isn't even on the agenda: The illegal abduction of Hong Kong residents by mainland agents, both in Hong Kong and in Thailand.

In large part because of Lam's revelations, Leung wrote to inform the central government of deep-seated concerns in Hong Kong over the case of the five booksellers — Lam and four associates — and to ask for a review.

Currently, the agreement covers only Guangdong province, adjoining Hong Kong, and Leung is asking for it to include all Chinese provinces. He wants Hong Kong to be informed if any of its residents are arrested, just as in the case of foreign governments. While this is certainly a step in the right direction, it steers clear of the sensitive issue of extralegal activities by the mainland.