To exclude all possible misunderstandings while crossing the border, I always told my tourists that for the visit of the Special Administrative Region of the People's Republic of China to Hong Kong, the validity of a general foreign passport of a citizen of the Russian Federation must be not less than 6 months as of the date of the end of the stay in Hong Kong, according to the rules of entry into the territory of the PRC, of ​​which it officially is . However, Hong Kong is known for its visa regime, loyal to foreigners, for example, for entry, so that the passport was valid only a month after the end of the trip, and for the British the main thing is that the passport was valid for the period of visiting Hong Kong, but for visitors from these countries and the period of visa-free stay in the Hong Kong SAR, Hong Kong is much longer than for Russians . I was faced with precedents when my tourists were denied entry due to the insufficient duration of the OZP when it was less than six months, but it was a few years ago . I sent an official request to the Immigration Department of the Government and the Hong Kong SAR, when a response with clarifications is received, I will necessarily give exhaustive comments on your question. - $ .

Response of the immigration department of the Hong Kong SAR Government:

According to comments received from the Department of Immigration of the Government Hong Kong SAR, for general international practice, the validity of the passport for entry into the Hong Kong SAR territory must be at least 6 months as of the date of the end of the trip .However, for citizens of those countries that have their accredited consular institutions in Hong Kong and, accordingly, who can be assisted in extending the validity of a passport of a citizen of a country, an easing is made and entry into the territory of the Special Administrative Region is permitted in case the validity of the passport is only a month apart from the period of stay .Consulate General of Russia in Hong Kong SAR and SAR MAKAO PRC: russia .com .hk .

But it should be borne in mind that different airlines make their demands for travel documents of passengers, including the validity of the passport, so you must specify the exact moment for the particular air carrier before buying air tickets.

I remind that according to the existing visa-free regime between the Russian Federation and the Hong Kong SAR, Russian citizens can stay in Hong Kong without a visa for up to 14 days .Nevertheless, the decision to enter is taken directly at the border and you may be denied entry ¥ $ ,if a member of the border control department finds ,that you do not meet the general requirements and do not give the impression of a respectable ,honest and positive person.,in connection with which on passport control you may be required to confirm the presence of sufficient amount of money ,necessary for the entire period of stay without the right to carry out in the territory of the RAA the working and commercial activities ,as well as a return ticket to the country of residence or to a third country ,with the exception of cases of transit to China or Macau

Visa requirements for citizens of different countries can be viewed here.

Thus, it turns out that both you and your colleague are right.