In a "normal" year the Company will pay 13th month salary. Most years are normal and this salary payment is an expectation of all staff.
The local staff in particular are very expectant each and every year for receipt of this 13th month salary. If for some reason it did not happen, then the local staff would be extremely upset.
The Company does not want to upset this very important element of their staff structure and also degrade the Company's status and standing in the Hong Kong community.
Precedent and Hong Kong Court rulings basically ensure that the 13th month salary is paid, except in the most extraordinary circumstances.