In fact, there is an example of someone prevailing over Delta airlines in a NY Small Claims Court, when they established that the airline was in breach of EU 261/2004. The evidence they submitted was the ruling by the Swedish Aviation Authorities that a breach of 261/2004 had occurred. The Montreal Convention also allows for the claims to be heard in the jurisdiction chosen by the plaintiff, which should be either the point of departure, point of arrival or the head office of the airline.
If you felt that Vancouver Small Claims was not the right forum, you can try and file a claim online in Ireland. Once the claim is filed, Air Canada would have 15 days to respond. Typically, the airline will settle the case before it goes to court, because it knows that it cannot prevail. You would be unlikely therefore to be required to appear. For advice on how to file your claim online in the Irish Courts, link here:
https://smallclaims.courts.ie/esmall...nguage=English