BG-E2 USA Warranty Card?

I just bought the Canon BG-E2 grip from DigitalFotoClub. It's supposed to be a USA Warranty version except it did not come with the standard Canon Warranty card.

I asked the vendor about this and they said that Canon will just ask for a proof-of-purchase (ie. invoice).

Can someone attest that this is true or am I just being BS'd because they sell gray market products but advertise it as USA?

Thanks!