Just shout out, "I'm sorry... I'm his... doctor!"
From Create Your Own Story
"I'm sorry, sir... I'm this man's... Doctor! Yeah! Yeah! He has a rare disease that can make him go crazy, and the only way to fix it is to... oh, you're pissed at me, aren't you?"
"Yes," he aptly responds. He whacks the victim one more time with the trash can and steps toward you.
Back off slowly, then turn the other cheek and run like hell.
