The rulebook for these events was posted on the Ohsweken website long before the start of the season, and the press release (from December 29!) announcing the events has this printed in it: "Canadian Sprint Car Nationals technical rules will apply."
So, what you are saying, Tommy, is that the evidence points to the persons/teams racing were in the wrong when they thought the rules were different.
Looks like an open and shut case to me - the evidence is clear.
But then again, Casey Anthony was just found innocent of killing her daughter. So, what do I know, eh?