In cases where a show is airing in both Canada and the United States, here in Canada it’s often the case that even if you turn the channel to the American station, the Canadian station will cut in so that you get the Canadian commercials instead. Once the show ends, if the next show is only being shown in the States, the station will switch accordingly (if you’re watching the actual Canadian affiliate’s channel and not the station being overridden, it will sometimes switch over to another American network). Sometimes this will create issues because the TV station will forget to switch to the next show until it’s already a few minutes underway, thus resulting in the wrong show being aired. Seeing the closing theme of a show twice because the Canadian and American versions are not in sync also happens.
And sometimes the reverse problem of the “asleep at the switch” issue happens. So once I was watching the Simpsons on the FOX station, only the Canadian affiliate was cutting in. It was the highly publicized first part of the Who Shot Mr. Burns episode and the show was just about to reach the end. And just before the shooting was to happen… the station was switched from the Canadian affiliate to FOX proper, which had already ended the episode. It wasn’t the first time that the Canadian affiliates situation had cut off the ending to a Simpsons episode but this was probably the most glaring. So Canadians in the area had to wait until next season not only to find out who shot Mr. Burns and what his fate was, they also had to wait to actually see the cliffhanger itself!