Can Canadian rulings set precedent in American courts, or is this just a case of the claimants demonstrating how the issue has been handled in other countries for reference by the court?
Precedence is odd and many-faceted, and in a case like this, it would be done indeed to show how other courts have handled the situation. If a Canadian ruling can give a bit of relevant guidance, than it is something that would be put into a case to help bolster the cause. Conversely, neither the judge, nor jury, has to take the Canadian ruling into consideration at all, as it isn't binding. Pretty much it's just helpful advice for the court to keep in mind.
American courts are not bound to follow any Canadian rulings.
They can choose to cite anyone who agrees with them as support for their position, no matter who it is, though. So they can certainly write something saying "look, everyone else agrees with us too" but this is not at all the same as when they're trying to act according to the past decisions of the courts that supervise them.
In one case, they're just looking for people who agree. In the other case, it's more or less mandatory. Yes, they can try to avoid following the precedent if they want, but the judges who supervise them can overrule them if they're out of line.
