The mistake of the poster made is, he was counting on the ULCC as a connection flight without leaving enough room for irrop - had he booked it as arrived enough early or even a day early for his YYZ-EU flight, then the delay of the ULCC arrival would not have much of an impact.
He is extremely lucky that the AC flight also delayed for departure so he has made it. Otherwise the potential outcome would NOT be pretty.
AC has no obligation to rebook him because he is not directly connected to the AC flight which is the first flight after the OJ.
Finally NO, he is absolutely NOT clear on why he missed the flight after the OJ because how he arrived for the next flight after the OJ, would make a lot of difference.
Very likely arriving from a Star Alliance flight, AC might be more accommodating. Arriving from an ULCC? might be an uphill battle.
If the AC is not delayed so he has made it, very likely the whole rest of the itinerary would be canceled by the system. tough luck for planning it so close to the limit. You dont do this when you are traveling on separate tickets.