On the CAA Quebec web site it says the Quebec DL is good everywhere in North America...except Georgia. It is on the page about getting an International Driver's Permit.
So, maybe there is something to this technicality.
I would worry about this if you haul illegal contraband, are caught driving drunk, speeding excessively or get stopped in some podunk speed trap town. In other words, they might tack that on if you did something really bad or are unlucky enough to get stopped in a town that gets most of their revenue from traffic fines.