He's correct
Unfortunately the BTC is correct if strict interpretation is applied, but there always has to be room for latitude, does a hello, good bye, or even more to the point a thank you if the controller has done you a favour imply poor RT . I don't think so unless the frequency is maxed out , then pleasantries are not appropriate, but conversely not giving the squawk code on first contact requires the controller to go back and ask for it. This lapse increases the controllers workload and the RT congestion far more than a simple good evening.
in defense of the Hong Kong controllers, I can understand that they are becoming so busy with the increase in air traffic that pleasantries have no place in their working lives but that shouldn't detract from the thoroughly professional job that they do every day of the year. From me to them, a big thank you for keeping us safe every day of the year and that trumps everything else.