Based on the results of the final exams I've given, no senior will fail to graduate because of the grade received in one of my courses.
I got closer to that Armageddon this year than I ever have before and it's not pretty. I won't accept personal responsibility for someone's failure to graduate, but neither will I take glee in assigning a grade I know to be fair when that grade results in a student's not graduating.
It'll eventually happen. That day will come, but it is not this day.