In canada if a fraudulent bank draft is cashed by the bank ,and cash given to the banks account holder ,who is held liable for the funds. The account holder was not aware the draft was a fake,and the funds were forwarded to another party. We now know it's a scam, and shared our concerns with the teller at the time, but draft was cashed anyway. The bank says we are on the hook for 2500 for a draft they cash, that came back.

In both Canada and the US, the bank account owner who cashes the check is liable to pay the bank back, In some parts of the US, if they don't, they bank can even press criminal charges.

As you noted this is a scam, it is one of the most well know published scams on the internet and in the world today, it has even been featured on the Oprah TV show.

So yes, if you cashed that check and sent money to someone else, you have to pay the bank back, you can try to collect from the person you sent the money to, but it will be traced out of the county and you will never see the money again

Unfortunately this is correct, if you had any doubts you should have left the funds in your account until the draft was confirmed as cleared by your bank.

Is this one of those obvious scams like you receive a check and have to forward 90% to some overseas company?

Yep the account holder who presented the check is responsible. However, you can try to sue the presenter of the check for reimbursement.