Used car dealership did not disclose 10k wreck. Possible arbitrage opportunity?

Hello everyone, I searched through the forums and mostly stumbled upon people discovering that their cars were involved in a wreck AFTER they signed the contract or bought the car. My case is thankfully different.
I managed to convince a used car dealer to drop the price on an SUV by almost 1.5k, which is around 10% of the sticker price. I did my homework beforehand and knew what the car was worth if it had a clean title and was accident-free. The price I managed to negotiate down to was only 700$ more than the market price listed on carfax's estimator. While I was a the dealership, I did my initial visual inspection where I took down notes, used a flashlight, test drive...etc. all the good stuff I learned from youtube and google. Knowing that I'm paying a premium for the ease of mind and legal protections offered through dealerships, I asked all the right questions (but did not record them) such as has the vehicle even been in a wreck (they say never and they can show me the clean carproof), was it a rental, how many previous owners...etc

After I got back home and seeing 6 other cars, I decided this was gonna be the one (it was mint clean for its age and perfectly fit my needs). So I bought a carfax for it and low and behold, the car has 10k in damage from a "LEFT FRONT CORNER" collision. I was pissed, so I looked it up and in my province MB, and found out that I am able to file a complaint against them since I have an archived link of the false-advertisement they have up on kijiji which explicitly says "clean-title and carproof".

Now here comes my question, should I just report them and move on? Or should I leverage this to my advantage as a true RFDer and demand the price to be dropped to 10k (sticker price 15.5k and carfax's estimator is 13.3k based on the VIN, excluding the damage report)?
If you suggest option #2, what would you recommend me doing? Should I ask them for the carproof and see if they provide me with a fake one, further increasing my leverage or should I just have a mechanic inspect it first to make sure the 10k damage was just bodywork and didn't affect the frame or mechanical components?

And let's say the mechanic clears it, do I send them my offer as well as confront them face-to-face or send them an email to keep a paper record in case they don't cooperate? Also, would this be considered blackmail or am I within my rights to demand a better price for not reporting them to consumer protection?

I know I'll be taking a hit in the resale value when I decide to sell it later on, but I'm planning on holding it for 10 years or so, so it doesn't really matter.

Looking forward to hearing your thoughts on this.