A lawyer who claims the concept for the popular web application Pinterest was stolen from him has won a ruling—extinguishing a cause of action advanced by his adversary—in his legal battle with an early investor in the idea-sharing platform.

But the federal judge in the case called the skirmish a “lightweight exhibition” match and noted the main event in the litigation—a trade secrets lawsuit against the investor—lies ahead.

In one corner is Theodore Schroeder, a 2006 Columbia Law School graduate who says he and two classmates developed an idea for a social media platform in which users can post their interests to digital bulletin boards, which differed at that time from Facebook and other leading social networking programs.