Randy Cohen writes "The Ethicist" column in The New York Times Magazine. If you'd like help with a moral dilemma you're facing at school, at home, or at work, send your question to: ethicist@nytimes.com or The Ethicist, The New York Times Magazine, 620 Eighth Avenue, 6th Floor, New York, NY 10018, and include a phone number.

I tied my sister's Jack Russell terrier to a fence while I went into a supermarket. I returned to see a woman being loaded into an ambulance. Bystanders said she stooped to pet the dog, and he bit her on the lip. I untied the dog and left. Had I stayed, I would have had to pay her medical bills. Why should I, when she provoked the dog?
L.R., Brooklyn, New York

ALTHOUGH THAT WOMAN WAS FOOLISH TO PET A STRANGE DOG, HERE'S WHAT YOU SHOULD HAVE DONE: SIT! STAY!

As it happens, you had no legal duty to stick around, according to Lisa Weisberg, formerly of the A.S.P.C.A.

And though laws for dog-bite victims vary from city to city, says Kenneth Phillips, an attorney who runs Dogbitelaw.com, almost every city has some type of "dog court" that hears victims' complaints and tries to determine whether the dog is dangerous. Did the Jack Russell meet that definition? I can't say—and neither could the lady in the ambulance, because you did not come forward.

The victim might also have wondered if the dog had medical problems, like rabies. You deprived her of knowing and perhaps sentenced her to painful inoculations.

I'm impressed by your certainty that the dog was "provoked," since you were in the market at the time and saw nothing. Amazing psychic ability!

(The New York Times Upfront, Vol. 143, December 13, 2010)