This makes me think of the line in As Good As It Gets
Receptionist: How do you write women so well?
Melvin Udall: Easy. I think of a man, and I take away reason and accountability.
My point is ahem that if your girlfriend takes out your new Jeep, sideswipes the garage wall, tears up your front lawn doing donuts or whatever, hits your lawn mower, knocks over a fire hydrant (or anything like that), and faults you for it, you need to get your shit together and find a non-psychotic girlfriend who is familiar with reason and accountability. But if you're going to have that attitude in the first place, you're asking for trouble. You're practically begging for someone to use you as their chew toy.
Fighting with your girlfriend is not shouldering blame that isn't yours, but nor should it be about laying blame. Working out disagreements as best you can while not hurting the other person is.
When you do fight, ask yourself "Is it Kind? Is it True? Is it Necessary?" If you can't answer yes to any of those, then don't say it.