My spouse who's a Canadian lawyer said a number of Canadian laws have referenced American (and historically more importantly British) law as examples during proceedings but they can't be cited directly as precedent case-law.

It's just a helpful data point when establishing new laws and assisting judges to form their legal opinions in cases without existing examples within Canadian law... and I'd assume also inspire Canadian lawyers to form their own class actions when they've already been tested in American courts.

I was just curious if foreign parties could play any role in American ones, which I doubt is the case.