SAN FRANCISCO — Yelp Inc. has by and large been able to beat back lawsuits seeking to pull down reviews by unhappy business owners. But on Tuesday, in arguments before the California Supreme Court in Los Angeles, the online review company seemed to be on its back foot.

The case at the state high court, Hassell v. Bird (Yelp), stems from a negative review of a law firm called the Hassell Law Group in San Francisco. The firm secured a default judgment against a former client, Ava Bird, that Bird’s Yelp review was defamatory. Then the trial court issued an injunction against Yelp to pull the review down. Yelp was never a party to the case.