So are insurers of drunk drivers going to be able to use this to not pay for damages?
No, the driver being drunk does not imply they are deliberatly intending to hit a car or have an accident . Most drunks would try to avoid that. So if a drunk driver hit your car he would be liable as long as his driving was the actual negligent act and caused the accident. If you make a left in front of a driver that is drunk then his drunkeness has nothing to do with the cause of the accident.