SAN FRANCISCO — In a decisive win for Orrick, Herrington & Sutcliffe, a federal magistrate judge has refused to certify a potentially massive employee class in a suit accusing CVS Caremark Corp. of failing to pay workers and reimburse mileage for after-hours deliveries.

U.S. Magistrate Judge Elizabeth Laporte of the Northern District of California concluded plaintiffs had failed to show a uniform policy or practice at the roughly 1,000 CVS stores in California that required nonexempt employees to make off-the-clock merchandise transfers between stores without compensation.

“Instead, the evidence is that sometimes managers or non-managers ask non-exempt employees to perform [inter-store transfers] before or after their shifts or while clocked out for lunch,” Laporte stated in a 21-page order issued Monday. But “even if an IST is performed off the clock, defendants’ official policy is that employees must be paid for all time worked … And there is evidence that this policy of paying for all time worked was followed at least as to some ISTs performed off the clock when the manager knew.”

Plaintiffs attorneys at Oakland-based Aiman-Smith & Marcy had sought to certify three classes of roughly 51,000 current and former CVS workers in Ortiz v. CVS, 12-5859. Orrick employment partners Tim Long and Michael Weil led CVS’ defense.

“The judge didn’t just rule that class certification was inappropriate,” said Weil, but based her decision on evidence that CVS actually required employees be compensated for performing inter-store transfers. “CVS did, in fact, pay people for time doing inter-store transfers and reimbursed them for expenses,” he said.

Laporte’s order noted that CVS kept few records showing which employees made the transfers, complicating the case. “The court would have to conduct mini-trials of all putative class members to determine whether that employee performed the IST off the clock,” she wrote.

Plaintiffs lawyer Randall Aiman-Smith said Laporte erred “by failing to place the burden on CVS to keep accurate records of time worked by employees delivering merchandise.”

Contact the reporter at mtaves@alm.com.