flyingcanadian – 01/11/2015 06:05 GMT
Please note that I am not a lawyer and thus my personal opinion is not derived from legal training and should not be relied on!
It sounds that the fault may fall within the scope of the regulation (I doubt it would be classed as extraordinary circumstances) and Air Canada, although a non-community carrier, is caught on flights from EU states.
However, the delay is measured on arrival (not departure) and would need to be four hours or more for compensation to be due under article 6, per the wording of the original regulation. Assuming a flight of 3,500kms or greater.
Here is a link to the regulation
Subsequently a case known as ‘Sturgeon’ introduced a ruling that flights with over three or more hours delay should be treated as cancelled and therefore article 5 would apply and compensation would be due.
Here is a link to more information about Sturgeon
The key question is how late was the flight, when the passenger door were opened on arrival?