With three pro tem justices on the bench and a roomful of lawyers hanging on every question, the California Supreme Court on Monday gave little hint how it might come down on a controversial defense raised by alleged price-fixers.

At issue is the pass-on defense, which 17 major pharmaceutical companies asserted in claiming that 17 San Francisco Bay Area pharmacies can’t seek damages for reputed overcharges on prescription drugs because they “passed on” the costs to customers.