There is no EU regulations applied. You did not board in DUB.

You can write to ET - but chances of getting something tangible are nil.

Your only recourse was that upon landing in YYZ you demanded a flight sooner, even if it required a connection on a different airline to get you to your destination. You did not have to accept the later AC flight. Your beef is with AC there, or whoever rebooked you. That should have probably been already arranged before you even left ADD if you knew youre gonna miss your connection.