What specific law was broken here, and how?

OP booked a just-inside-the-rules connection, and it sounds like an AC employee screwed up when trying to short-check his bag as a courtesy. This is almost certainly AC's fault, and deserving of compensation for OP's out-of-pocket costs at minimum, but as the old saying goes, "never assume malice where incompetence will suffice".

As for rebooking him onto later flights, even a one-person IRROPS situation is not the same as IDBing people off of an oversold flight, nor does it require that empty seats be held available each day on other flights to accommodate misconnected passengers.

The only flight for which IDB might apply at all would be the originally-booked YYZ-YEG, and from what we've been told so far it doesn't sound like that one fits either.


Lots of things would be worse if we chose worst-case hypotheticals.