I'd appreciate some advice on a possible 42-minute connection in YYZ, which marries an award flight with a revenue ticket between YOW and YVR.

I'm in Toronto for a stop-over on the inbound portion of an AP J-class award ticket, ZRH-YYZ-YVR. I'm scheduled to fly the YYZ-YVR leg departing 18:00 on Sunday, Jan. 18. I just found out, however, that I need to be in Ottawa from Friday, Jan 16 to Sunday Jan 18. So, I need to buy a ticket to get me back to YYZ in order to catch my 18:00 flight (I failed miserably in trying to charm an AP supervisor into tacking on a YOW-YYZ leg to my award booking).

I can buy a YOW-YYZ flight leaving at 16:00, scheduled to get into YYZ at 17:18. That gives me 42 minutes to catch the YVR flight. I won't be checking any bags. If I miss my flight to YVR, what will AC do? There's lots of room on the later YYZ-YVR flight departing at 20:00, FWIW. However, I've been told a connection should allow at least 45 minutes, and since I'm off by 3 minutes I'm SOL and I will have no recourse...is that accurate?

Thanks in advance.