Real purchases require real people, so simply asking who the buyers are should sort it out. If employees were filling out the forms and “buying” then it should be fairly straightforward to figure out.
For some reason the Canadian iZEV rebate was provided to the dealer, not the end customer. Dealers were to sell below cost and then get money back from the government, so they'd be on the hook for the difference if they couldn't get the rebate. The rebate was scheduled to cut off in March but was obviously running out of funding before schedule. Dealers had some leeway to batch their claims and Tesla sent an unprecedented number of claims right at the end that drained the remaining funds, but these claims are not necessarily all for sales from that small window. I can't find any specifics but surely the claims submitted have to substantiate that a car was sold to a Canadian resident. I'm still not sure that Tesla did anything illegal unless they are found to have sent fraudulent claims, which should be trivial to check.
It's really not. That's Tesla saying that one-fifth of its annual sales for the entire country of Canada happened on one weekend in one part of the province of Ottawa.