Used car warranty denied by dealer?

My girlfriend bought a used Subaru from a local Subaru dealer. Recently we experienced some mechanical issue with the vehicle and it's suppose to be cover under the extended warranty but we were denied such claim. Reason is that the dealer accused us of damaging/caused the problem ourselves. We have no experience or much knowledge to be messing around with this. The only thing that I can think of is our local GoodYear shop. The last time I was there for an oil change + wheel alignment was 7 months ago. The damage was said to be something with the tire bearing and axel. Missing nuts and not installed properly. Though it has been 7 months, my girlfriend don't use this vehicle much so of course stuff doesn't break down until certain mileage. Please look at the photo and tell me if a poor wheel alignment job could've cause such damage? Some advice on what I should do next would be great. Subaru headquarter took the dealer's words and turned me down on the warranty as well. Image: https://s31.postimg.org/u6o2sk0zf/IMG_20160720_100...