Flights from Toronto to a US destination would most likely be code share, whether operated by United or by Air Canada. It's the flights from a major center to a more "remote" location that aren't code share. If you have one of those on each end of your flight, the fares go up a lot, because one airline buys a separate ticket for the "foreign" leg from the other airline and adds it to the fare from the "domestic" (code-share) portion.

, so perhaps the bachelor-party weekend also included (slightly early) cake and candles in his honor.
).

