Of course I took you to task. The statement was patently illogical.
"The 'person with alcohol' behind the wheel is BY DEFINITION at fault."

no

The person who caused the accident is BY DEFINITION at fault.

Think of the implications of your statement.
If no one has been drinking is no one at fault?
If both have been drinking are both at fault?
If the Drinker is parked in a parking lot and a texting teenager hits the drinker's car is the drinker still at fault?