Did AC acknowledge an error on their part, or did they blame user for not clicking a final confirm, refreshing their itinerary, not notifing that no new email was sent, etc.

Claims for involuntary denied boarding or disruptionn delay under airline control seem to need properly issued ticket at the time of checkin/travel.

Odds are poor, near zero for $1000 Canadian APPR delay regulated compensation, but it costs that same zero amount to file. The wheel they spin to give APPR-accepted responses often gets stuck on "required for safety".

They likely don't owe EU compensation either, but the odds of getting an airline held accountable (with a more accurate explanation of what happened each step) increase astronomically. 600 euros paid out as cash if the travel bound affected originated from Europe before arriving in YVR.

If all you do is ask AC what they owe you, they will likely generate you a 10% off coupon. aka "sorry for the issue but we want you to GO AWAY!! on another trip"'