**UNBELIEVABLE ** 
I am lead to believe that the security in HKG is pretty good, so there has got to be more to this. How did he get thru security - did he have a photo ID with the old guy’s photo? I cannot imagine getting thru with a mask like that in a carry-on, if he donned that mask post-security.
If 55 is “elderly” what does that make me ?
Here is how he did it.
He picked up his boarding pass and passed thru all security points using his own ID without the mask on.
Just prior to boarding the plane, he entered a bathroom and put on the mask. He then switched boarding passes with a friend - who is a 55 year old white guy.
He then used an Air Canada Aeroplan Card (looks like a credit card) and the boarding pass to enter the plane.