Hi ygsam,
Yes, the tax treaty between the UK and Hong Kong, article 14(2) advises that employment carried out in Hong Kong is taxable in Hong Kong, but article 14(2)(a) goes on to advise that if you spend less than 183 days in Hong Kong, then it is only taxable in the UK.
For this reason, you will need to claim a tax refund in Hong Kong and declare the income in a Self Assessment tax return.
UK/HONG KONG DOUBLE TAXATION AGREEMENT AND PROTOCOL
Thank you.