There might be legal consequences to doing that. People have been arrested for jumping the line and getting a vaccine meant for someone else before, though that was when the vaccines were just arriving and being distributed to vulnerable individuals. Since they record your health card, it's possible they'll check the records, see you've gotten 2 first doses and you might have to deal with the cops later. Of course, you won't know for sure unless you try. They may just fine you instead, or cancel your second dose appointments and give them to someone else. I don't know.
Noone was arrested in this country for jumping lines
They were arrested for side effects of it
eg BC Couple flies to Yukon to get first crack at vaccine by lying where they plan to work; their arrest was for violating Quarantine requirements.
Group said they planned to drive through Canada to get to US but stopped off (illegally) to get vaccine at pharmacy.
If you have a source for any actual arrests go ahead but beyond moral issues there is no actual law being broken
(not all places even ask for health card number when you go on waiting lists either so I doubt they would notice it before you go in)
That's weird how your shot went
Hospitals will book 1st and 2nd shot at same time I have seen (eg when you are scheduled you get dates for both shots)
Maybe pharmacy are diff