The guy has cancer. Give him a break. He made a mistake going to the wrong place, and was probably a bundle of nerves worrying if he is going to have any serious side effects. There is something wrong with the stops and checks if he got the wrong vaccine. May be there is complacency on his part that he felt he didn't need to ask " Is this Biontech pfzer" because he trusted the system to be fail proof.
But something went wrong, and in HK there are a lot of illiterate people, old people who are senile or confused, homeless people, people who may not be very educated and they will need the vaccine too. So there has to be a system to make sure they get the right vaccine.
I don't understand how he could have gotten the injection if his HKID card is not registered for sinovac.