Yeah, Riders fan here and I don't think stressed is the right word. Surprised, maybe. But not stressed. I don't even know if I'd go as far as frustrated. I got the sense that the Bombers were confident that they knew they would overcome these challenges and thus had nothing to worry about. And the Riders never really gave them any reason to doubt that.
That said, the Riders were actually very close to pulling off the upset. If Lauther makes that FG or at least gets a single out of it, then the Riders only need another FG to win/tie and the final drive they produced would have given a very good chance at it. Sure, it took a whole lot of Bomber mistakes to enable that scenario and only one Rider mistake to miss it, but the possibility was there.
Hamilton can replicate a similar scenario by keeping the Bomber offense in check. For the Riders, it wasn't necessarily the turnovers themselves that kept them in it but rather the Bombers not ending their drives in points. Two-and-outs can achieve the same effect. And since Hamilton was able to completely shutdown Stanback in the ESF, it's not unreasonable to think they can do the same to Harris. And I think that gives them a real shot at keeping Winnipeg's offense in check.
The only question is whether Hamilton's offense can muster enough success. Having two capable QBs will definitely help. But I think if Hamilton's going to win the game, they're going to need to win the 4th quarter and that's something nobody has managed to do against the Bombers all season. First time for everything, though, right?