Wal-Mart Stores Inc. may have opened the door to yet more legal troubles when it fired the lead plaintiff in a sexual harassment lawsuit last week, along with the woman’s husband, according to their lawyer.

Cory Rosenbaum of New York’s Rosenbaum Faria said on Thursday that he is preparing to file retaliation charges against the retailer over what he called a “bizarre” decision to fire his client and her husband just weeks after the sexual harassment suit was filed.