"Put down the knife! Put down the knife!"
It turned out that he was deaf.
I myself once asked a stranger to dial 9-1-1 for me, as, being mentally ill, I realized I was becoming quite severely symptomatic.
Six - count 'em: SIX! - California Highway Patrol cars appeared damn near instantly.
"How can we help you?"
"Could you give me a non-emergency lift to a psychiatric hospital?"
"The dispatcher told us you had a knife?"
"I was using a razor blade to trim the spines from prickly pears." (The fruit of a cactus. Tasty, if you cut the spines off first.)
The head patrolman scolded me for not taking better care of myself, then one of the others gave me a lift at 140 miles per hour to a fast food joint.